These days, many of us want a home security system. But a caution — if you sign up for one, make sure you know the penalties if you ever want to get out.

Alarm caution: Man charged $1,000 to cancel ADT by: John Matarese. ... Many of its alarm systems are sold by third-party vendors, though, and terms and lengths of contract can vary.

SimpliSafe even offers extra panic buttons (there's already one on the keypad), which you can press to trigger the alarm and dispatch police. One system can have up to 100 sensors connected at a time.

Custom home security systems by Brinks or Tyco are typically expensive affairs, leaving frugal, hyper-cautious folks to DIY their home security systems—which often amounts to nothing more than ...