Seems that board owners are not modifying the sigs....
For whatever reason.... I guess they don't want the
PR leaking out anyway....
Seo only account for less then 1 percent of all theme message boards..... Most board owners and users have no idea why they would benifit from even having a sig, let alone even know how to create one....
Google implementing such a filter would be a success to 99% of it's target.