The BBC’s weekly The Boss series profiles different business leaders from around the world. This week we speak to Christian Kroll, the founder and chief executive of internet search engine Ecosia.

Christian Kroll wants nothing less than to change the world.

“I want to make the world a greener, better place,” he says.

“I also want to prove that there is a more ethical alternative to the kind of greedy capitalism that is coming close to destroying the planet.”

The 35-year-old German is the boss of search engine Ecosia, which has an unusual but very environmentally friendly business model – it gives away most of its profits to enable trees to be planted around the world.

Founded by Christian in 2009, Ecosia makes its money in the same way as Google – from advertising revenues. It earns cash every time someone clicks on one of the adverts that appears above and beside its search results.

Ecosia then donates 80% of the profits it makes from this to tree-planting charities. To date it has funded more than 105 million new trees, from Indonesia to Brazil, and Kenya to Haiti.

As obviously not everyone clicks on the adverts, the company estimates that, on average, it takes 45 searches to raise the 0.22 euro (20p; 26 US cents) cost of planting of one tree.

Today Berlin-based Ecosia says it has 15 million users. This is a tiny drop in the ocean compared with Google’s estimated 5.6 billion searches per day, but Christian says he has grand ambitions to “scale massively, win more users, and plant billions of trees”.

And unlike the billionaire founders of Google – Larry Page and Sergey Brin – he promises to never buy a super yacht. “While they have big yachts I have an inflatable dinghy that I take to lakes. Ego consumption is not appropriate in a world where there’s climate change.”

Christian would, in fact, struggle to buy a yacht if he ever wanted one, as he put two legally binding restrictions on the business – shareholders and staff cannot personally sell shares or take profits outside of the company.

Born in the former East Germany in 1985, Christian wasn’t always so altruistic. As a teenager in the town of Wittenberg, he and his friends would play the stock markets, often trebling their investments.

He wanted to become a stockbroker, and so enrolled to study business administration at the University of Erlangen-Nuremberg in Bavaria.

However, his world view changed when aged 18 he went travelling for three months through India. “I met smarter people than me who didn’t have the same opportunities because they weren’t born in Germany,” he says. “It started dawning on me that maybe I should do something to make the world a better place.”

Then at university he first started to pay close attention to online advertising when he set up a website that compared different online brokers. “I was shocked at how much of my revenue I was spending on Google ads to bring traffic to the site,” he says.

And so his idea for what would eventually become Ecosia was born. “It became clear to me that Google had a very smart business model, and it was also fairly obvious that there was space for a purpose-driven search engine to do something similar… to use the money to fund tree planting.”

After university he spent six months in Nepal in 2007, where he first tried and failed to launch a search engine to raise funds for local charity and non-government projects. “I didn’t know how to launch a business, funds were limited, and most days there were internet and electricity issues.”

He then spent 10 months in South America where the level of deforestation that he saw gave him the determination to launch Ecosia in 2009 after he had returned to Germany. The name is a mixture of the words “eco” and “utopia”.

Christian says he got the business up and running with the help of others. “The truth is that I didn’t have the technical knowledge to do it, but I was able to rely upon the skillset of friends and family,” he says.

Today Ecosia employs 70 people, and it publishes financial statements online every month. Last year it had annual revenues of €19.3m (£17.3m; $22.8m), and a pre-tax profit of €14.5m.

All of its electricity comes from solar power, and 80% of its users are said to be 29 or younger.

Its search engine uses Microsoft’s Bing’s technology, with whom it has a long-term arrangement. “They really like what we are doing,” says Christian.

Eric Haggstrom, analyst at business research group Insider Intelligence, says that Ecosia and other smaller search engines face “significant obstacles”.

“Most importantly, Google provides the default search for Android devices, and the Chrome browser,” he says. “And it spends billions of dollars a year to be the default search provider for Apple devices.

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“Most users won’t use search engines other than their device or browser defaults. And on the ad side, advertisers use Google’s search product because it performs [so] well.”

Christian admits it “can be tricky”, and wants regulators to do something to loosen Google’s grip.

But more generally, he wants to see capitalism changed for the better. “This is really needed in the 21st Century,” he says.

“What we’re trying to do is reform capitalism. I think in its current state it’s not healthy. I want us to rethink how business should be, what the role of business is.”

‘Worst offenders’

Discounts

A TikTok trend where people pretend to be Holocaust victims is “hurtful and offensive”, the Auschwitz Museum says.

Users have shared clips of themselves with fake bruises, wearing clothes that Jews were ordered to wear by the Nazis.

The museum – at the site of the former Nazi concentration camp – said some of the videos on the app were “beyond the border of trivialization of history”.

But it warned against “vilifying, shaming and attacking” those who have taken part.

The trend has been heavily criticised on social media as “disrespectful” and “disturbing”.

In a statement, the museum says: “Stories of people who were imprisoned and murdered in Auschwitz are incredibly tragic, painful and emotional.”

It adds that some of the videos “were not created to commemorate anyone but to become part of an online trend”.

“This is very painful,” the museum says in the statement posted on Twitter.

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However, it adds that the “motivation of some people” posting the videos came “from the need to find some way of expressing personal memory.

“They use the symbolic language familiar to them.”

Rather than shaming those who participate, it should be used as an “educational challenge”, the museum says.

The Holocaust saw the genocide of six million European Jews people and more than a million people were killed at Auschwitz between 1940 and 1945.

TikTok has not yet responded to Newsbeat’s request for comment.

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Twitter has suspended a number of accounts for sharing a viral message claiming to be a Black Lives Matter protester who’s now planning to vote for Donald Trump’s Republican Party.

The message was shared by a seemingly inauthentic account using a profile picture of a male model.

Since then, it has been copy and pasted multiple times.

A Twitter spokesperson told the BBC the accounts violated its rules “on platform manipulation and spam”.

Where did it start?

On 23 August, a Twitter account called @WentDemtoRep shared a tweet that received more than 37,000 likes and 11,000 shares.

The account was set up this month and used images of a male model who was quick to call out the account.

“I can’t believe some pages are using me as profile picture without asking me for permission. Disrespectful,” Nelis Joustra tweeted on 24 August.

It remains unclear who was running this account or posted the initial message, which also appeared on social media site 4chan.

The account has now been removed, as has a similar one set up shortly afterwards called @Democratwent.

‘Super inauthentic’

Prior to the account’s suspension, it was spotted by Jordan Dixon-Hamilton, a law student and legislative intern to US Congressman Paul Gosar.

He decided to share the viral message on his own Twitter account @sirhottest during the second night of the Republican Convention on 25 August.

“It seemed super inauthentic to me, so I figured it would be funny if I copy and pasted the post,” he told the BBC.

“Lo and behold, a few more of my followers thought it would be funny to post as well until the point it turned into a meme and hundreds of accounts were sharing the message.”

Soon many more accounts were sharing the message. Most appear to be Republican supporters and other users who enjoy trolling.

Like @kpopobama who tweeted the message and told the BBC: “Yeah I’m not a Russian bot or anything I just like memes.”

Another called James said he shared the message “to add to the chaos”.

Other accounts sharing the message had been set up more recently. That includes one called Principled Conservative, which features a profile picture of a cartoon President Trump.

Principled Conservative told the BBC: “I heard that Twitter was auto-deleting accounts that posted this copypasta. So I used my spare account to check.”

‘Hostile foreign powers’

A number of popular pro-Democrat Twitter accounts soon expressed concern that the copied and pasted messages were part of a foreign interference campaign.

One user with more than 50,000 followers said: “Hostile foreign powers are using Twitter again to sway the election for Trump.”

The concerns come following evidence of Russian interference on social media during the 2016 US presidential election.

However, sources close to Twitter say these accounts do not appear to be linked to a state-backed operation at this time.

The origin of the initial message remains unclear.

The New Zealand stock exchange was knocked offline two days in a row due to a cyber-attack.

NZX said it had first been hit by a distributed denial of service (DDoS) attack from abroad, on Tuesday.

The exchange said the attack had “impacted NZX network connectivity” and it had decided to halt trading in cash markets just before 16:00 local time.

Trading halted briefly for a second time, on Wednesday, but was back up and running before the end of the day.

A DDoS attack is a relatively simple type of cyber-attack, in which a large array of computers all try to connect to an online service at once, overwhelming its capacity.

They often use devices compromised by malware the owners do not know are part of the attack.

Genuine traders may have had problems carrying out their business.

But it does not mean any financial or personal information was accessed.

NZX said the attack had come “from offshore via its network service provider”.

The second attack had halted trading for a large chunk of the working day – from 11:24 to 15:00 local time, the exchange said.

But despite the interruption, the exchange was up at the close of business, near its all-time high.

New Zealand cyber-security organisation CertNZ issued an alert in November that emails were being sent to financial firms threatening DDoS attacks unless a ransom was paid.

The emails claimed to be from well known Russian hacking group Fancy Bear.

But CertNZ said at the time the threat had never been carried out, beyond a 30-minute attack as a scare tactic.