When's the last time there's been a streaker even? I've seen people run onto the pitch here and there, but they're always clothed. I haven't seen a streaker ever except once I think - wasn't there a naked guy running around court-side during the last Australian Open or something? Other than that one incident, which I can't remember very well, I can't remember anyone streaking anywhere, in the last couple decades.
Can you imagine Fat Bastard running naked down the street? You can? Oh I'm so sorry...
Ugly porn may be a niche thing, but the niche exists.