Sometimes security doesn’t need to be overly complex to be effective. Instructables user [1234itouch] recently built a simple laser tripwire alarm that can be mounted virtually anywhere, comp… ...

Real Time Home Security System using GSM Technology-An Anti-theft System! This project deals with the design & development of a theft control system for home, which is being used to prevent/control ...

How to build your own simple laser trip wire alarm. The author of 'Arduino Project Handbook: 25 Practical Projects' takes us through the steps.

The device also keeps track of temperature and humidity. The entire system can be controlled via a web interface. The Arduino serves a web page that allows the user full control over the alarm.

Here is an ultra simple Arduino Night Alarm project wired around a handful of inexpensive and easily available components. One advantage of using Arduino as a security system is the flexibility!

Making your own security system isn't too hard, but if you'd like a super cheap and simple method, Instructables user deba168 shows how to make a wireless motion detector with an Arduino.

However, if you’re just looking to catch a sandwich thief at work or a cat spilling over all you water bottles, then Make shows you how to build an alarm system with an Arduino and a USB camera.

How to create a simple laser trip wire alarm, taken from theArduino Project Handbook: 25 Practical Projects to Get You Started.