Some practical joker put up a sign in a McDonald's
(emphasis in original):
As an insurance measure due in part to a recent string of robberies, African American customers are now required to pay an additional fee of $1.50 per transaction .
Dead giveaway: the term "African American" - racists don't use that term :-) Heck, a lot of non-racists avoid it.
But seriously...while there may be nutcases that might suspect an international corporation of having inherently racist leanings, I doubt that even that kind of whackjob would suspect that a corporation would put up a sign like that. Everyone knows that such a sign would be an instantaneous lawsuit invitation.