Click It Or Ticket

Noticed that recently, all the L.A. Story-style freeway signs carry the phrase "Click It Or Ticket" on them. I have no idea what the message behind that is. Google to the rescue: It's a campaign to get people to use their seat belts. Wow.

1. Who doesn't use a seat belt?
2. Who decided the phrase needed no more explanation to link "click it" with seat belts?