Women in Brussels 'filmed without their knowledge' by men wearing Meta smart glasses
(www.brusselstimes.com)
Legally, you don't.
And while indeed CCTV used to mean that it's closed circuit, today it now refers simply to camera systems installed for public (in the sense of non-clandestine) surveillance purposes. Given most these systems are cloud connected, they're hardly closed circuit, right? Yet we still use the term.