It’s always great to see people all over the world finding novel uses for our products. Here’s one from Italy from the Andrea Millozzi Tech blog. It’s in Italian but if you hit the Google Translate button, it does a pretty good job.
SIM card for burglar alarm-domotics, GSM remote control to operate devices with SMS text messages and advice for purchases to make good deals
The post was written in 2016 so the relative prices are a little out of date, there are many more choices of SIM tariffs to choose from now, and of course they only apply in Italy!