[gh05t3d]

i use At&t,the ip of the router is static.

[Gitzer]

AT&T doesn't automatically assign static IP addresses to devices connected to the dynamic WAN. In order to have a static IP (range that is) you have to pay more for that service. If you're visiting sites under different dynamic IP's but keeping your cookies and history intact then that's one way they'll track you.

If you want semi-anonymity then a VPN is the easiest way if you're not versed in networking. If you're too cheap to pay then use a TOR browser and call it a day.

If you're next question is, "What's a TOR browser?", it is time to start reading on internet anonymity....