Never mind Maria's Law, maybe you should support instead Kez's Law; which would restrict the wearing of a sock and a sandal on the same foot to parts of the interior of a shoe shop with no clear line of sight from outside, and for no longer than necessary to establish whether or not the sandal fit the foot satisfactorily.
'Cause as minging as wearing socks with sandals might be, it is still not quite[/j] as minging as trying on a pair of shoes with no socks and then putting them back for somebody else to try on. And you might reasonably expect to see people trying on shoes in a shoe shop.
(Also, perhaps it should be made a requirement of the MoT test for the stereo not to be audible to a pedestrian at a safe distance outside the vehicle. Otherwise, you should be made to purchase a Performing Rights Society licence for publicly performing copyrighted works.)