Originally Posted by
makeinu
And how will the best lock I can afford do? No matter how it's locked with some basic tools any amateur bike mechanic should be able to strip a locked up bike of everything except the wheels and whatever part of the frame is contiguous to the rear triangle (basically everything that isn't a loop or welded to a loop).
This is true, and if your folder were equipped with all Dura-Ace components, I would be worried. But I don't think the person who stole your seat did so because he wanted to resell it (I don't think that there is much of a market for used seats); I think he did so because he saw that he could. In other words, you were more the victim of vandalism than theft.