Hook for persuasive speech about not using social networks?

[Sunchan]

I need a good hook for my persuasive speech about how we shouldn't using social networks such as facebook and twitter.

I already have one that is lyk "Facebook! Twitter! What comes into your mind when you hear these words?"

but I feel lyk it's not attention grabbing enough,, any ideas?

Thank you

[Nelda]

How about the obvious,
"Do you want to risk marketing companies getting hold of your personal information?"
Those 2 sites make money by selling users personal info to marketing organisations.