I sent you a note but then I ate it

I'm wracking my brain (I think that's the first use of the word wrack on this blog) trying to think of a situation where I might want to use this, but the concept is intriguing.

At privnote, the idea is that you compose a note, send the link to the note via SMS or email, and once the recipient has clicked on the link, they will see the note in their browser and the note will automatically self-destruct; which means no one (not even that same person) will be able to read the note again. The link won't work anymore.

It's interesting, but if the point of the tool is to be able to deny that you sent the note in the first place, all the recipient has to do is take a screen shot of the note while the link is still up and save the image as a file.

So pardon me if I don't quite get it.......