By reading closer the service descriptions and contracts I get that all cheaper offers for unlimited 3G, actually some sort of sub–EDGE offer once one reaches the given 1 or 3Gb limit, they are all made for using into a phone. Putting the SIM into another device, like a USB modem or WiFi HotSpot, would be a breach of contract and reason to close the line.
I've read about guys doing it without restriction. But I also know the system (…)