Recently, when helping some folk on the Forum I've noticed they had installed bogus or rogue antispyware programs. I've been fooled too. One such program I recently used wanted to remove blocked sites that I had setup in IE (or were part of SpywareBlaster's blocked list) - i.e., it was finding, so called, 'false positives'. (Having said this some of the 'good' ones also get it wrong on occasion!)
While some of these bogus programs find 'false positives' to entice users to use/buy their dodgy products, others resort to aggressive/deceptive advertising, are simply inadequate, have no update feature, are rip-offs (of well-known legit programs), are adware themselves, etc., etc.
click here to see quite a comprehensive list of such programs & sites. For a list of the good/legit ones - click here. There are further links at the bottom of the first site which point you to more bogus/legit programs & sites.
The disclaimer on the first site says, "the author of these pages has no financial relationship with any of the companies whose products are discussed on these pages. I am not an employee, affiliate, representative, or other agent of any of these companies."
I suppose, in the end it's up to you to decide which ones to accept or reject. Thankfully, most of the common ones we use, like Adaware, Spybot, SpywareBlaster/Guard, PestPatrol, Spy Sweeper, CWShredder, HijackThis, etc., are the GOOD ones : )) Hope this is of use to somebody, G