ISTANBUL — In the cartoon, an image of Recep Tayyip Erdogan stands watch while two thieves empty a safe full of cash. “No need to rush,” one of the thieves says with a grin. “We have a holographic watchman,” he adds.

The message in the cartoon, published in February in Cumhuriyet, an opposition newspaper, was unmistakable, coming as members of the Turkish leader’s inner circle were targeted in a corruption investigation.

Mr. Erdogan was not amused. The offending cartoonist, Musa Kart, who had a history of drawing cartoons critical of Mr. Erdogan, was taken to court on charges of insulting the prime minister (now the president), violating the privacy of an investigation and committing libel. Mr. Kart was acquitted in October, leaving him free, for the moment — Mr. Erdogan’s lawyer has appealed the decision — to keep challenging authority with his caricatures of Turkey’s rich and powerful.

“This repetitive cycle of legal actions affects all cartoonists, writers, intellectuals in this country,” Mr. Kart said. “We will continue to work and express what we think for the good of our future generations.”