Call me crazy, but I always thought you can use those models for:
A) Personal Use
Or
B) Non-commercial Use (many indie-games I’ve seen use ripped-models)
Correct me if I’m wrong, but if you (or anyone for that matter) are using the models for commercial purposes (you are gaining revenue from the product) you are in fact committing an illegal act. If NO revenue is gained (or the money you get is by donation only) you can use the models to their full extent so long as you give the proper credit.
~ Jason