Yes if you abuse it you can end up being penalized by having rich snippets removed or even worse.

How could they be abused i.e what are the dos and dont's?
I haven't used them yet though I have seen them on some sites.

If used properly, rich snippets can contribute a lot in driving organic traffic to your website. Excessive use or abused used of anything is bad and may lead to penalty.

E.g not putting a big red border around a picture of the product your promoting with a save xxx% sticker on it