Originally Posted by catatonic
Problem with running a lock through the frame is it allows a thief to use the frame as a lever. Sure the bike may be trashed when they get it, but they still have plenty of components to sell off at the flea market/swap meet/craigslist/etc.
True, you can still attempt to perform a leverage attack on a "sheldon locked" bike, but the thief is more likely to just pop the wheel out of the dropouts. Yes, your bike will still be mangled, but at least you have something that can be repaired, and not just buying a whole new bike (or spare parts if it costs too much to repair and you buy a new bike anyways).
Indeed. That's one reason I'm advocating the two-locks, two-posts technique that I included the photograph of in post #4. It pins the bike at two points (three, if you use the cable to cinch the frame to the parking meter up at top-tube level) so it can't be effectively used as a lever. It also should discourage thieves from even bothering to try, since it's obvious at a glance that your bike isn't going anywhere until two locks are defeated. If you're going to carry two locks, might as well make maximum use of them...
Use any method you want, it's up to each owner to assess the risks and pick their preferred technique. I'm not entrusting my own bike to a technique that I can defeat with my bare hands and a 6-inch diagonal cutter. All the thief would need is a rear wheel, tire and tube and he'd have a whole bike again.