Doesn't this already happen?
Now there's someone out there passing a tbow down a chain of accounts, knowing he gets to keep what he took (because Jagex very publicly always lets them know they get to keep what they steal).
Imagine if your local police department issued a public service announcement that they would no longer return stolen possessions, but simply punish the very first person in the chain that took the possessions with jail time.
Do you think your house would be safe? No. There'd be a handful of grunts (starter accounts) in jail, and the thieves would literally own your house. Meanwhile, the police are patting themselves on the back proudly as they look at the grunts they caught. "We're doing a great job keeping people's property safe", they say