Re: GDPR says no?
Does GDPR say no? A Mac address (or an IP address or an email name) is 'potentially identifiable' - but there isn't a blanket ban on holding the data. If you have a reason to store it, store it securely, and don't use it to identify an individual without their consent you can store it. So if my reason was 'monitor performance of my wif router' and the log was on a secure drive I'm ok. If my reason is 'identify repeat visitors to my coffee shop' or I leave the list on a train I'm not. So as long as someone with that address logged just calls up Police and says - I saw that MAC address, and leaves it to the police to do the CCTV thing, I don't think GDPR has been violated. And fairly certainly any 'public' wifi will have a 'the right to monitor and collect information while you are connected to the Service. Any information collected may be used at the discretion of the operator, including sharing information with law enforcement agencies e.g. for the prevention and detection of crime, the apprehension of offenders and other applicable legal requirements." clause in the small print.