Possible Duplicate: What is the difference between: Rooting, Jailbreak, ROM, Mod, etc Is either possible, legal, contractually legit and does either damage the phone?

I'd like to know if android phones are sim-locked. Given that they are open-source and have community images it should be 'tricky' to sim-lock one but I prefere to ask. Also - do I need to unlock if I use dual-sim adapter with one legal card in it?