If the owner of the data doesn't voluntarily share it, sure. Same as they need a warrant to search my house, unless I invite them in for a cup of tea.
But who is the owner of the CCTV data? The 7-11, or the guy on the tape? If the former, then that's the same as how phone call records are handled in the U.S. The government is getting these call records with AT&T/Verizon's cooperation.
(In the UK), the 7-11 owns the recording, but the person shown on the tape has the right to inspect the recording as they please.
Inviting them for a cup of tea is not the same as authorizing a search of your house. Yes, they can look around at what's on sight but they can't start taking out your drawers and searching them.