The headline is misleading. The Pirate Bay as a whole has not been branded anything by Google. Rather, certain pages using bayImg and an affiliate ad network

The headline is misleading. The Pirate Bay as a whole has not been branded anything by Google. Rather, certain pages using bayImg and an affiliate ad network were detected delivering adware or something malicious. So, Google's software detected this only on those pages, not the Pirate Bay as a whole, and now Chrome and Firefox now display a warning when trying to access those specific pages on thepiratebay.se. The Pirate Bay is aware of the problem and they are working to clean-up their ads. The scary messages will subside when the ads are fixed. Pretty much a non-story.