An ideal version of this mechanism would work like this: once you commit a patent to the fund you can not use it offensively in the future (to avoid worsening the problem), but you'll be protected by the "patent fund" when someone sues you. The sum of the patents of lots of small companies could quickly be enough to deter most suers that are not patent trolls.
Disclaimer: I'm not american so my knowledge of the patent system is quite superficial, perhaps a similar mechanism already exists?