Hi I am reading more and more articles with regard to laptop security.I also am wondering about the battery of a laptop apparently some people try to sell there second hand laptops just before the battery is going to die because the batter of a laptop from my understanding is expensive to buy a new one. is this correct?

A random laptop security article says:http://www.pc1news.com/news/0155/sec...p-owners-.html
then Wiki says http://en.wikipedia.org/wiki/Remote_Laptop_Security which is about remote laptop security and what to do if it is stolen.

My questions therefore are:Is laptop security so bad that it isn't worth it to get one although I need one badly and my second question is if the battery life isn't so good how do you know if someone selling a second hand laptop if it has a battery that is expring?

thanks any information would be helpful