Why let it slide?

Perry de Havilland says we shouldn't give people wearing Che Guevara t-shirts a free pass.

[D]o not shrug off efforts to portray people who wear images of communist mass murderers as jackasses rather than 'cool' as wasted effort over something something of no account. Little things like this add up and if you believe, as I do, that the single biggest factor determining the triumph or defeat of liberty is a cultural expectation of liberty, then fighting for the cultural issues really does matter. And if the lumpen wearing the Che Guevara tee-shirt does not even know who he was, as will often be the case, then tell him in no uncertain terms so that next time he looks at his pile of shirts, perhaps he will think twice before putting it on and maybe, just maybe, look at other people wearing those vile tee-shirts a bit differently.