Not all longboarders
are unsafe
There are plenty of "safe" longboarders out there that don't zip in and out of traffic or even on busy roads at all. Don't use some apparently clueless girl without protective gear dodging around a road full of cars as an excuse to ruin an amazing new sport for everyone - yes there should be laws regarding skateboarding - but it should not be banned completely. City ordinances (give them the) right to do what they want so far.
Shoreline recently made it illegal to longboard anywhere in the area even the neighborhoods.