I'm actually more worried about crooked baggage handlers that works in the airport than fellow travellers..:s
If your worried about your luggage that much, just buy a bag and carry it on. I've had no trouble with my luggage and it'll be more than obvious if you check it in and it doesn't come out of the chute with the rest of the luggage. And would all the baggage handlers be in this little scheme, or would one just walk away with luggage? I suppose they would carry the luggage out of the way of their next job and would stuff it in their "lockers", right?