1. Sometimes when I'm logging into my e-mail account and I'm typing my password in the cursor somehow automatically clicks itself back onto the username and then if I don't realise it fast enough everyone will be able to see my password. Can anyone explain what is going on here?
2. This used to happen on my PC at home until I changed mouses/mice. It recently has been happening on a few public computers too. The mouse sometimes adopts a life of it's own and all I see is the cursor zooming off to and fro and often clicks on random things. Explanation?

Thank you in advance