Lenses and cameras are usually prime theft targets. Most of the thieves steal to sell, so if you lose any photographic equipment, you should keep checking your local Craiglist. It is also a good idea to have insurance that covers theft or loss.
Insurance is a must-have, especially when your future income and net worth ties up in the photography equipment. When you consider the expense, you realize that the coverage of risk is worth much more.
I agree with you both. Most of those that steal may not have any interest in photography. These items may get sold at throw-away prices. During purchase, a photographer may also want to check if the manufacturer allows them to register as an owner.
I think stolen goods are more likely to show up in pawn shops than anywhere else because it leaves less of a trace. Also, it's important to record your serial numbers so that you can report it to local pawn shops and they'll know to keep an eye out. Hopefully.