We do not need an extra person per ride to enforce it.... we need people around that person(s) to tell us of the problem, we can't always see it. If I ever see anyone, I tell them to put it out... But we can't tell them to stop if we don't see it! As for the shirts.... If it is just words, I do not care. Kids probably don't even understand, but if there are pictures to the shirts that are not good, then I think they shouldn't wear them. Kids will understand that!
P.S. What is the point of wearing clothes like that anyways!??