Google is offering to buy patents in a “simple, easy to use and fast” process while letting the seller continue using the relevant technology. It’s billing it as a way to combat patent trolls, but it’s by no means an act of philanthropy.

According to Google, the purpose of the program is to deal with situations where people who come up with patented technologies either want or need to quickly sell the patent, for example to solve cashflow problems. It argues that at the moment such sellers will usually find the only viable option is selling to a patent troll (also known as a non-practicing entity): a company that holds patents solely to use as a legal weapon rather than to manufacture or develop technology.

Google’s answer, the Patent Purchase Promotion, will run as an experiment from May 8 through May 22, during which any patent holder can offer a patent to Google and name their own non-negotiable price. Google will then make a decision in principle by June 26 about which patents to buy. It then has a target of completing all purchases and handing over the cash by the end of August.

While it’s designed as a streamlined and simplified process, Google points out that “selling patents is serious business” and recommends that all potential sellers consult an attorney. One of the key conditions is that the purchase process on offer is very one-sided: simply by submitting a patent and price, the seller is committing to selling at that price, but Google retains the right to pull out of the deal at any stage before completion.

The good news is that as part of any purchase, the seller retains a licence to use the patented technology. This lasts forever and applies worldwide, with no licensing fees or royalties required, but isn’t transferable.

Google isn’t making any firm commitments about what it will do with the patents, other than to say they’ll be added to its general portfolio. This means Google could develop technology itself or license the patent to other firms (including rivals of the original seller.) Google has previously pledged to only ever use patents defensively in court, meaning it won’t sue an alleged violator unless it sues Google first, but that pledge is likely not legally binding.