It's possible, but I think in this case, it was probably because Stratasys became AWARE of this. I believe that it was a purely arse-covering move on Stratasys' part. If they allowed it to continue, being fully aware of what their equipment was being used for, and someone out there decided it would be ultra cool to take these plans and continue on their merry way, made a full plastic gun, and it exploded and took off their fingers - well, I'm sure that Stratasys would have some kind of legal case thrown at them. This way, they have been seen to be taking action. I don't necessarily agree with their actions, but I can understand their viewpoint too.