LAUSANNE, Switzerland (Reuters) – A dozen Swiss climate activists appeared in court on Tuesday after refusing to pay a fine for playing tennis inside branches of Credit Suisse bank last year in a stunt intended to highlight the bank’s fossil investments and “stop people acting like nothing is happening.”

The young activists, mostly students, were fined 21,600 Swiss francs ($22,254) for trespassing at Credit Suisse branches in November 2018. Lawyers for the students who are appealing the fine said on Tuesday they were acting as whistleblowers for the climate emergency.

“..It is not enough to just go out on the street or to vote, we must disturb a little bit so people stop acting like nothing is happening,” Castelain, one of the activists, told Reuters outside a courtroom in Renens, a suburb of Lausanne.

Video footage from 2018 shows students in tennis whites playing matches inside Credit Suisse branches in Lausanne and Geneva to underscore Swiss tennis star Roger Federer’s sponsorship deal with the bank, which they want him to drop because of its fossil fuels investments.

Federer did not immediately respond to a request for comment via his Foundation.

Credit Suisse, which had filed charges against the activists, said it respected their cause but deemed their actions unacceptable.

“Combating global warming is important,” it said in an emailed statement. “Credit Suisse respects freedom of expression as a fundamental democratic right. [However,] to protect its clients, employees and branches, it does not tolerate unlawful attacks on its branches, irrespective of the perpetrators and their motives.”

Pressure is rising on Switzerland’s financial sector to divest from fossil fuels and thousands of students have marched through Swiss in recent months demanding action on climate change. A swing to the left in an October election has boosted their demands.

Credit Suisse in December said it will stop financing the development of new coal-fired power plants although activists at the court said this was not enough.

It said on Tuesday it was also seeking to align its loan portfolios with objectives set out in the Paris Agreement on climate change.

A ruling is due on Jan. 13.

($1 = 0.9706 Swiss francs)

(Reporting by Cecile Mantovani, Emma Farge, Marina Depetris and Brenna Hughes Neghaiwi; Editing by Alexandra Hudson)