other users will be disconnected?

when restarting computer, was notified that the 50 users connected would be disconnected. There should not have been other users; was I being hacked?? Thanks!!

No, you're not being hacked. It is entirely possible, however, that your wi-fi network is being shared with strangers. Do you have a password on it? Might want to consider changing it. Are you using a community Ethernet connection like a college dorm, apartment building's connection, something like that?

Also, go into your System Preferences, Go to sharing and UNcheck anything that's checked. Make a note of what was checked and let us know.

No other uses set up as WPA2 Personal and use a 13 digit password, containing numerals and letters, with some caps included.