That's interesting. I've done a good deal of work in all three verticals and introducing a restricted license in any of their environments would have been a tough sell that involved a legal review and a well documented business case. I can think of a few where I can guarantee they would never allow it - and not based on any problems with React's license in particular, but because of internal history.

I wouldn't be surprised if the choice of front-end framework for website development is still below the radar of legal/compliance for some of these places..

A lot of these groups still see front-end tech as just HTML and CSS..

What sort of things would banks, telcos, and insurance companies typically patent? These don't strike me as innovation-oriented companies.

If you don't have any patents, you're not really risking anything using React.

Are you joking, or you just don't know? Telcos alone have a huge list of patents which they are happy to use in the courtroom, and they have won cases in the millions USD. Verizon ranked 52nd in the world for patents granted in 2016.

Bank of America was ranked 124th for its number of U.S. patents granted in 2016.

http://www.ipo.org/wp-content/uploads/2017/05/2016_Top-300-P...

wouldn't that mean that your company is covered by the react clause but your clients aren't? of course they're not worried, if they're a separate entity they aren't the one in the agreement.

We typically deliver pages and/or SPAs into their existing environments, where these libraries are already installed globally, so I don't think so.