Do I need firewalls if I have a router?

Episode 1175 (2:05:59)

Joe from Canton, OH

Joe just got a router and wants to know if he really needs firewalls anymore. Leo says no. Joe could turn on the Windows firewall, but any third party firewall isn't really needed because the router is essentially a "dumb box" that prevents attacks from incoming traffic.

Routers, though, aren't impervious to attack, so he'll need to keep the firmware up to date, or even use a third party firmware like Tomato or DDWRT.