I’m confident Durov was arrested because the platform he was responsible for is a hotbed of illegal activity, most of which is not under the cover of encryption.

That was Durov's biggest mistake in retrospect. Man should've taken some lessons from Megaupload's demise and gone all the way on E2E - would've given him plenty of plausible deniability if he genuinely couldn't have known what any of his users were doing.

It would've arguably brought other problems, but it would've removed that golden opportunity for the gendarmes to nail him.

Would've likely also earned Durov some brownie points with privacy nuts, as well.