Oh yeah, and definitely change your WiFi password from the default that your manufacturer or ISP sets. They can tell the manufacturer from the MAC address, and intuit the complexity based on ISP or manufacturer docs.
The ISP in the Raleigh area I was on uses a default password that can be intuited based off the router model and MAC address: both of which are broadcast by default. AT&T is better, but you can still glean the default length and charset used from just the MAC address.
