If you're looking at legal reasons, it's certainly against their terms of service.
https://business.comcast.com/terms-conditions-smb#sthash.ghwh6KqH.dpuf
Edit: also if any of them do anything illegal, it's on you since your name is on the service.
Hi guy's, iv'e given 2 people in my building my Comecast wifi pass word as they can't afford their own.
Now someone else asked to use it..Like the title say's what issues could I have and am I stupid to have given it?:can: