The difference is that in this case, the street owner was explicitly notified (made aware of) the fact that Immortan Joe was using his road to rape and plunder, and the street owner responded by providing cover for these activities instead of stopping them.

Backpage (allegedly...) played an active role in conducting sex traffic by posting its own ads and modifying third-party ads for child prostitutes to make them less obvious to authorities. Like Silk Road, there is no deniability-- they know damn well what business they're in, so they don't get to play the "b-b-but we were just running a website!" defense.