I read an article once about bicycle couriers in the US disguising their bikes so they didn't get stolen. They used to wrap inner tubes etc around the tubes to make they look rough.
No one I knew thought that an inner tube wrapped over a glistening Stumpjumer frame would fool a bike thief into thinking it was anything but a decent bike. Even druggy thieves aren't complete idiots and will know what "Deore" means as opposed to "Exage".
Inner tube wraps were mostly favoured because messengers have to lock their bikes up 40 times a day, as quickly as possible - so you want to protect the paint.
There was also a feeling a bike marked as a messengers was less likely to be stolen - because a crook knew that within 5 minutes of taking it, an entire company's worth of messengers would be looking for it.
Tape around the frame won't deter a thief much either. What will, somewhat, is covering a frame with hundreds of crappy individual stickers. They're horribly time consuming to remove and make the frame recognizeable as well as less attractive, limiting it's resale value. So a thief *might* decide to take another 5 minutes to look for another bike - unless the frame has desirable components on, in which case it's worth taking even if he throws the frame away.
The only way to prevent this (other than the obvious one of only having cheap components) is deface stuff with a dremel, epoxy, and/or paint. Which obviously kills the resale value!