I agree with the concept of this thread, but I don't think it's as simple as just throwing a thread out there with a general call to post websites. The listings need to be substantiated or the risk is run that revenge for an unrelated, non-business issue will be a motivator for posting. Of course, that is assuming anyone takes enough interest for it to matter.
Also, discussion will inevitably lead to this becoming a flame thread, and we already have had enough of those.
Don't get me wrong, I don't think this is a bad idea but the truth is that LPF already has a pretty comprehensive list of offenders already throughout the "companies" section and more get added all the time. That's what this section is here for.
Taking that into account, the real burden of protection falls to the consumer. The more people use the search function before they buy the better it will be for them. It's really easy: If you want to know if the company you are considering buying a laser from is reputable, just plug the name into the search bar. You'll get an idea fairly quickly in most cases, and if you don't find anything there, ask here in the Companies section. Most likely someone will be able to tell you something about them.
IMO