If you recall the older style garage door openers had the static (single code or frequency) but
they changed the technology years ago to a randomly fluctuating code and so have nearly all
car alarm manufacturers. It is really not all that difficult to acquire a frequency, and if a thief is
familiar with X10 single code technology and is aware you have a X10 system (maybe it was your
cable or satellite TV installer who noticed your $10,000 plasma TV) he can add you to his list.
It's a scary thought, but it could happen. Perhaps there is a way to add rolling code technology
to the X10 system.