There was a thing on TV about this. People drive around looking for unsecured wireless connections to download illegal stuff through through someone elses router and it is the router owner who gets in trouble and has to pay the fines. It is YOUR router and YOU must secure it or you are responsiable.. That is what they said.

My neighbor bought one to hook up to my computer and we had it set where only he could use it. You go into your computer to do it but I forgot how. There should be instructions in the manual that came with it that'll tell you how to secure it.

The more people who tie into your connection, the slower your connection will work.