Alarms can be a good investment, especially if you have many valuables in your home, live in an isolated area, or one with a history of break-ins.

• A false-alarming or faulty security system is worse than no alarm at all!  Check with several companies before you buy so you can decide what level of security fits your needs.  Do business with an established company and check references before signing a contract.
• Learn how to use your system properly and make sure all family members understand!  Don't "cry wolf" by setting off false alarms- people will stop paying attention and you'll probably be fined.

Alternatives

• Sound detector that flashes an attached lamp, or "barking dog" recording when it detects certain noises.
• Motion detecting out-door lights that turn on when someone approaches.
• Photo-cell activated lights that turn on when it's dark and off when it's light.  

Sunnyvale Alarm Ordanance