A couple of years ago I threw away all freebies collected for as long as I've been online (some 8-10 years) and am now making sure it clearly says "can be used in commercial renderings".

As a computer game creator using rendered 3D images with hundreds of objects through out the game I have to be very careful with freebie objects (if I use any) making sure they can be used in commercial renderings.
Our first game (released 2000) sold very well even though it was released only in Finland. Our next game will be sold in several countries with consequently, more exposure so to avoid eventual lawsuits one must be overly careful.

Besides that I'd take the opportunity to thank all fantastic freebie makers - if I use your object you will be mentioned in the game credits.