I would STRONGLY suggest you change your WiFi password. If you need help in doing that I can help you over the phone for free...PM me if required.

If you are sharing your connections, and your neighbours do something ILLEGAL on the net, you will be the one it will be traced back to. I know this might sound unlikely but I have heard of many such cases where people have been viewing illegal indescent content using someone elses internet and the original internet owner was arrested for it. Please think about this before you every share your password.