I just read somewhere that one of the features that FireFox 2.0 will include is an extension blacklist. The purpose is to help prevent attacks. Really, I see this as being a potential problem. That would seem to allow web compatibility issues to continue. If companies block JavaScript files in an attempt to stop JavaScript attacks, all JS would need to be inline. That would really sacrifice performance on an AJAX capable web app and also cause some browser caching issues. What do you think?