Stolen Apple device - Serial Number Issue

I have recently lost my iPod touch device through property theft. I had iCloud on and "find my iphone" as well. I have found that no apple device can track without the help of cellular of wifi, however though using the device I can track my movements on mapping apps without actually being connected to any particular wifi or cellular network. This form of tracking does NOT work over iCloud functions, so there is no way for me to track my iPod touch. I have been told by Police to obtain my serial number which is registered to my apple account. What concerns me is that according to other posts people can hook my iPod touch up to another computer and iTunes, wipe it clean and re-register so they can use it themselves. Now I remember that when using older Microsoft programs I had to enter a serial number and register it online to use the program, and if all "uses" had been used I could not register and use that program. Similar I should assume applies to apple with its sophisticated policies, that a stolen device has to be registered before syncing with another computer by way of serial number and that I should get an email to say that somebody is trying to re-register my device on another computer. The same prompt system used for apple password changes. My main issue is that the iPod touch is forever registered to me unless I remove it, but does Apple allow a thief to register the same device, the same serial number twice? If that were so, there are laws in most countrys that would classify this as an accessory to a criminal act, allowing and encouraging a black market of stolen apple goods. Apple puts up a front with its "find my iphone" app, but doesn't the world agree that serial number tracking of registrations should play a part. I can give my serial number to the Police, but only apple will know if somebody has tried to register my device a second time. In short, can my iPod touch be wiped? (it is locked). Does apple have a policy indemnifying them of criminal black market activities? Can apple notify me if somebody tries to re-register my property? Can apple block re-registration attempts?