Wireless unlock remotes

I purchased my truck in California and have since moved to Colorado.  The wireless door unlocking remote that came with the vehicle gave me no problems in California, but I have noticed that the remote sets off alarms or unlocks doors on other GM vehicles in Colorado.  Makes me wonder if they ship particular frequency remotes to particular states with the assumption that vehicles will stay in the state where they are sold.  It’s an interesting phenomenon and makes me a little concerned that if my remote can activate other vehicles that other remotes can activate mine.