1) None. But you can backtrace through ISPs. IT forensics is a very printy trail that can be followed. YOU might not know your IP, but your ISP should have it on record for a time.
2) Get real. When an *authorized law enforcement agent* tells a company to co-operate, they do. Period. Ever told a cop "no" on something? It does not go well. If they walk in the door w/a warrant for the data, it is happening.
It is also just a matter of Netflix pulling records from a DB. Might be archived, but probably still not that big a deal. Even w/a disorganized network not built for data mining or tracking, my boss and I were able to pinpoint a specific laptop location at a specific time on a specific day in our network, and prove who stole it via the IP records. Cops were called. Issue resolved. We DID have a harder time pinning dn one we saw sign on OUT of district, but only because it involved going into records for a private residence out of our site. We still could have applied to the ISP (our director may have, tho some fear of being accused of racial profiling, as it was a poor neighborhood, was being discussed by mgmt, IIRC).
3) And robbery is still a big deal. At least, if the lawful owners fit a certain demographic that the local enforcement is not biased against. It goes on a pile, but it gets looked at. GTA would get more an immediate response, but it still gets done. Rape reports, btw, still get sidelined a disgustingly large amt of the time. A lot of victim-blaming still goes on.
4) Yes, I agree here, tho one can still push the issue. Not having the serial IS a problem.
5 and 6) Stolen property goes back too the lawful owner in every state, period, w/actual honest buyers losing out on the $ they paid. More, thieves tend to have records, and a known thief w/hot goods is charged, immediate proof or no, in many cases.