You can monitor people based on water and electricity usage; it's less detailed, but you can get some information from it. Marijuana grow houses are commonly fo

You can monitor people based on water and electricity usage; it's less detailed, but you can get some information from it. Marijuana grow houses are commonly found through power usage signatures. In fact, they commonly steal power not just because they use a lot of it, but so they're not instantly detected. The new "smart meters", which provide much finer grained usage, will be even better for surveillance.