You'll never have definitive proof because the vast majority of people in media doing fed work are assets and mostly unwitting assets. They're not actual case officers, meaning they'll always be plausible deniability. For stuff like Breadtube, all the feds have to do is create thousands of fake Patreon accounts and funnel money to the channels they want to platform. The only Breadtube channel that's actually close to a witting asset instead of an oblivious useful idiot is that Southern anarchist larper (I forgot the dude's name) who got busted trafficking Ukrainian (?) women. It's pretty obvious he's taking marching orders from some handler. But for almost everyone else, it's just useful idiots getting platformed by the feds through (not so) clandestine means.