Paranoid ? I doubt it, there are unfortunately a lot of "Free" programs out there that carry unwanted passengers and SiteAdvisor is a pretty good way of checking things out. But you do need to read what it says carefully and check the dates on postings as there's no way of editing comments once posted and some ageing transgressions end up hanging around blackening reputations ad infinitum.
I suspect that the program you have in mind is Spyware Terminator a program produced by Crawler a company that had links with Ibis who have/had a bad reputation. All I can add to SiteAdvisors clear rating is that I've used it for several months now, never been spammed and backup checks with S&D have never found anything untoward. It has far more features and a higher degree of automation than almost all the other freebies and I like it a lot.