I am by no means a software developer but I think you would want the extension to validate proper sites as opposed to invalidate bad sites. For example if it validates proper sites it would have a green check (much better to have no default image and force users to set a personal image) every time you signed into a proper Steem platform by the sign in. If it is invalidating websites then it would have to invalidate all non-Steem programs to be truly efficient against scammers and thus could get annoying and lead to users uninstalling it.

While I have free time (seldom at times) I wouldn't mind to look at starting it (but you'll not see progress for a long time because as I said I'm not a software developer lol) but I think that it would be better for someone like @r351574nc3 to really get it set up within the next decade. Regardless I also resteemed in hopes of finding actual minds that can bring a product to everyone. Thanks for shining a light on op sec @runicar!