Since most Volvos are "boxy but safe" - shaped with aerodynamics somewhat similar to that of a brick, and they're Swedish...the discussion group focused on Volvos was named "SwedishBricks".
The name stuck.
Sometimes the group is referred to as Volvo.net or S'bricks...No matter what it's called, though, we're all Volvo lovers. Many of us have owned more than one (or 10) Volvos, some dating back to models built in the 1950's (PV 444 anyone?).