From the Wikipedia page:
On 11 November 2023, it was alleged that Tuta was being used as a honeypot for criminals with a backdoor from authorities. An ex-RCMP officer, Cameron Ortis, testified that the service was used as a storefront to lure criminals in and gain information on those who fell for it. He stated authorities were monitoring the whole service, feeding it to Five Eyes, which would disperse it back to the RCMP in order to gain more knowledge about the criminal underground. However, no evidence was ever presented to back up this statement, and Tuta refuted the claim.[22][23][24]