Reality Check! The store doesn't... they don't HAVE to... Sony already has that covered. It's called a License Agreement (http://www.scei.co.jp/ps3-eula/ps3_eula_en.html) which you agree to the instant you break the seal on the box. Welcome to THE LAW people.
And for your information (like you'd read it anyway): 7. TERMINATION
If SCE determines that you have violated the terms of this Agreement, blah blah blah, HERE'S WHERE OL' MIKEY'S DOOMED>>> implementation of upgrades or devices intended to discontinue unauthorized use, or reliance on any other remedial efforts as reasonably necessary to prevent the use of a modified PS3â system, or any pirated material or equipment. SCE and its licensors reserve the right to bring legal action in the event of a violation of this Agreement. SCE reserves the right to participate in any government or private legal action or investigation relating to your conduct. Jail time is the LEAST of ol' Mikey's worries, because he's also opened the door to all sorts of legal action against himself.