Idea for a change to the terms of the licenses people get for free and buy from the site:
If a user, free or paid, sues anyone for infringing a patent using software available through the site, all their licenses for software offered through the site terminate immediately.
This is basically the “defensive termination” provision of many common open source licenses, but widened out so it terminates licenses for all projects for a suit against any one of them.
I have some legal homework here, to check this under various jurisdictions’ competition laws. I’ll probably start by having a look at the terms for “blanket licenses”, the ones music performing rights organizations issue for their music catalogs, to see if they include similar protective terms.