@dethos Even more interesting. This request has been "in development" for some time, received comment from Mozilla employees (beyond the community manager), and has requests merged in which specifically mention this idea. It looks like Mozilla has been laying the technical groundwork, and now has the infrastructure to block specified extensions on specified sites with that warning. The caveat is that, in this early stage, all of the specification is done by them - the specified extensions are presumably just Mozilla-recommended/reviewed extensions, while the specified sites are (for some reason) opaque and seemingly arbitrary. Most odd, but hopefully to be better explained soon.