Our Web site features the highest standard of encryption available. With this state-of-the-art security, your personal data is scrambled before it's transmitted through the Internet.
--flyer from MBNA, received 11 February 2006
I suppose that this isn't exactly a malaprop, because technically the statement is true--your data is "scrambled" when it's encrypted. But the connotations I have for "scrambled" make this amusing to me.
On the other hand, I suppose the term "scrambled" is in common use for this kind of thing in some contexts. Spies in movies use "scramblers" to talk secretly on the phone, for example. So maybe there's nothing really wrong with this.
Still, I was amused by it.