We turn ours off at night, so we obviously log off then. We don't worry about hackers too much during the day because DH has put up a pretty good firewall. We did have a hacker once, but that was because he had messed with the firewall so that he could do some stuff for work. He sat down at his computer and saw that someone else was logged in. The hacker destroyed some of his Windows files, so he had to reformat. But DH fixed the firewall, and we've never had any other problems.