Telegram CEO Pavel Durov. Flickr/TechCrunch A group of Russian activists are taking legal action after they claimed their accounts on popular messaging app Telegram were hacked into.

The Financial Times reports that the activists aren't suing Telegram, instead they're going after Russian communications company MTS, which they accuse of helping someone illegally gain access to their accounts.

Oleg Kozlovsky and Georgy Alburov claim that they found that their Telegram accounts had been accessed by someone who requested confirmation codes sent via text message. They don't know who gained access to the accounts, but they say that MTS turned off their ability to receive text messages shortly before the hack.

Telegram CEO Pavel Durov has a history of run-ins with Russian law enforcement. He was investigated by police for allegedly running over a police office (which he denies,) and posted a photograph on Instagram of him giving the finger to authorities after they gained control of VKontakte, the social network he founded.

Durov told The Financial Times that "this is technically possible everywhere, but democratic countries typically try to avoid intercepting SMS without a court order, because such measures are highly visible and can lead to public uproar."