I have yahoo mail, and I just hooked up my computer and got online, but someone else is signing on to chat on my connection. Usually when I turn on my computer, I"m already signed on, so I"ve never had to sign on before, but now that someone else is signing on, I can't chat until I learn how to sign on to chat, or maybe figure out how to prevent other people from hijacking my internet connection. I can't seem to find any information on the internet.