Here i read: "if you are using a public wireless access point for example, the access point will log your network card MAC address, time and date. A network administrator could use this information to link your machine, i.e. laptop, mobile device, etc, with a particular Internet session, in order to do that you would have to lose control of the device and allow someone to examine it, using a VPN on a Wi-fi connection will not hide your MAC address." Now imagine this situation: i have a laptop which in the past i used at home ,no vpn, my regular isp. I now use this laptop at a wifi location (,earlier without vpn ,now with vpn) . Is this theoretically possible: The hotspot, (say, a big fastfood chain)lets law enforcement sniff their traffic, LE spots an interesting person, and with the mac adress they obtained they query their database and find the same mac adress was used when this laptop was connected to my isp; so, i am exposed. If the above is a correct assumption,what steps should i take to become anonymous ? 1. Change the mac adress when i go online ? 2. Remove the network card physically and use a new usb card(which i would have to buy anonymously, and never use it with my own isp because then i would be identifiable again) I would appreciate your take on this.