Why would someone with malicious intentions ever provide their real details? Why would someone provide their real details anyway when they will most likely be used for advertising/marketing tracking and spam?
They might have been interested in having the MAC addresses to check some suspects alibi, or even to find some links between groups of persons, not specifically PII.
Grenoble is under scrutiny for some time now, it has a bad reputation regarding drug trafficking and the government uses it to show its "strength" with police operations covered by the media. This might be linked.
