What we can do in GNU in regards to new technologies considered trap, as users will be lured to launch non-free software without possibility to verify it is to expand or extend the LibreJS to verify Webassembly programs for their licenses.
It is easier, and far more practical to recommend to solve the problem in a different manner than try and verify all running code in the world. RMS has to get involved on this, as to devise a method how to make sure that Webassembly programs are free software. Why don't you take it up and try to devise this method? It would not only be useful for web browsers, but programs in general. A white list of websites offering Webassembly as free software could be compiled as well. It is easier to simply deal with the problem by avoiding running random code automagically. But if you think such a list is possible, would you like to start working on it? Firefox is already warning users of abusive websites reported by users, which run Webassembly. If you can convince the firefox developers to do it, it sounds like it would be useful.
