The Pirate Bay is indeed a technical trailblazer. Not necessarily for back-end architecture or user experience, but damn, the site is resilient against anything you throw at it.
Pretty much every Power That Be <tm> has tried to bring the site down, and it still stands.
I imagine that the operators have absolutely no connection to the pirate bay. Access by Tor, pay to PRQ with an anonymous method (they even do cash), and there's really very little risk in it for them. The money flow could very well be followed, but one would hope they have planned for that.
You have to give those guys props for stamina.