No who uses snapchat think it's super secure as everyone realises you can just take a screenshot (app detects this and notifies the sender), or you can just take a photo with another camera.

It's just about making it harder for the average user to save a potentially embarrassing photo and allow you to send fun pics that are too crappy to put onto facebook/twitter.

Not a big deal because the real use case is a user that doesn't want someone else (say parents or SO) to come along later and find the pictures.

Agreed, but, do most of the users of SnapChat care?