That is hilarious. So the alarm was just perpetually going off without a siren? Or did they finally rip it out?
I had a similar thing.
I bought a used motorbike not as a toy but because it was by far the cheapest commuting method for my journey at the time.
Anyway, after searching for a cheap one I realised that I could get a real bargain if I was willing to travel about 200 miles into the sticks, even with travelling costs included these things were going for peanuts there because they had such a limited market.
So I travel down and pick it up, the guy tells me it has an alarm on it but it doesn't work. I ride it all the way home over the next 4 hours and well I'll be damned, the further I go the louder the alarm gets. Turns out it had some sort of internal battery and because the guy had just been doing little journeys on it the damn thing had gone flat while he owned it.
I took it to a garage and they managed to get it in service mode but couldn't do anything else because it was defective. They quoted (IIRC) about 30% of what I'd paid for the bike to remove the alarm because it was wired into EVERYTHING, the bike would need a total rewire.
Needless to say, I rode around on that thing in service mode for the next 2 years. It made a loud beep every 30 seconds.
If you listen carefully you can hear it about 6 seconds into this video -
https://www.youtube.com/watch?v=S6j1_ox5EdY I didn't notice it after a while and I wore earplugs on the bike anyway. I did get some strange looks though.