I really don't understand why everyone is all up in arms about this... first off- unless the mags have a manufacture date on them showing after 7/13 there is no way to prove you did/didn't own them before or after the date; second- I highly doubt police are going to go out of their way (when many are already busy enough with the day to day stuff) to inspect your magazines; third- the burden of proof is with the prosecution, remember that innocent until proven guilty? That still stands... so far.