Originally Posted by Mr_Super_Socks
Remember, though, it takes a special spanner to loosen the couplings - a tool few thieves are likely to have handy. If the couplers are properly tightened (i.e. really, really tight) they can't
Yes, I think they take a proper tool if you want to disassemble them nicely. If not, well, a monkey wrench/pipe wrench will work just fine. It might not even be bad for a one time removal (or emergency tightening!) that allows someone to pedal away. That tool's probably in any thiefs arsenal, because it's the best way to grip something small and with a lot of force (ie. holding a chain link while cutting it with a portable cutoff tool).
I don't think it, in terms of theft or tamper prevention, is even analogous to how Torx were years ago or square headed bits were.
edit: I was thinking more along the lines of channel locks above