Serious question then... what's the deterrent? Sounds like a person could spend all day looking for packages, resell the contents, at the risk of just paying a small fee if one happens to prosecute...
Welcome to the reality. Typically, the criminals are caught with lots of items, and there's theft and possession of stolen property. Or if they are stopped, they are also carrying drugs and they'll get charged with that.
Edit: Also, its not so easy to sell a bunch of random things for the cash. For every iphone that might get you a 100 or so in one transaction, there's a bunch of random things that you might get you $20 if you spend a day trying sell them.
Edit: Also, its not so easy to sell a bunch of random things for the cash. For every iphone that might get you a 100 or so in one transaction, there's a bunch of random things that you might get you $20 if you spend a day trying sell them.