Tldr, to help fight patent trolls:

They’re asking you to find evidence of preexisting technology – referred to by patent lawyers as “prior art” – that can kill off bad patents. This could be open-source documentation (including release notes), published standards or specifications, product manuals, articles, blogs, books, or any publicly available information.

They use this info to essentially undercut and invalidate the patent trolls’ filing, killing their ability to file suit on that patent again.

There’s also a contest with a $3000 prize for anyone who can help kill a current one on their plate.

https://patroll.unifiedpatents.com/contests/s3vQkRdTC6coNkjyx