So, here's my advice. If you're a merchant just know that you don't have to require a signature and you may be irritating your customers by doing so. If you're a consumer it doesn't make a difference whether you sign that receipt or not — there's no added fraud protection other than what your credit card company already provides. You can raise a fuss or just politely mention it to the store manager. Or better yet just move on and add it to that list of little annoyances that will eventually go away over time.