“Only you can silence yourself. Make them hear you. Register to vote now…” is the message Hollywood star Jessica Alba seems to deliver in a new bondage-themed campaign for Declare Yourself.

“I think it is important for young people to be aware of the need we have in this country to get them more active politically,” said Alba, 27. “People respond to things that are shocking.

“If you don’t register and vote and make a difference, and hopefully change the bad things that are happening in our country, you are essentially just binding and muzzling yourself.”

Declare Yourself’s “Only You Can Silence Yourself” PSA campaigns typically show celebrities crying with their mouths forced shut. A 2004 campaign with a photo of Christina Aguilera showed the singer with her lips tied up with leather string. Another ad showed Mean Girls actor Jonathan Bennett silenced with screws and bolts.

ET will broadcast a behind-the-scenes clip of the photo shoot for the upcoming campaign and brief interview tonight. Watch the preview here:

How was it for Jessica to be aimed at by Marc Liddell’s famous lens?

“It didn’t freak me out at all,” said FHM’s Sexiest Woman in the World 2007. “What I like about Marc’s work is that he tells a story and brings real emotion to his pictures.”

Declare Yourself is a nonprofit organization that encourages young people to vote and the campaign conveys powerful messages about the importance of voting.