Um...

I really don't give a shit if a 23-year old smoked a bong. As far as I know, Michael Phelps isn't running (or swimming) for office and the last time I looked, he's not exactly the ONLY 23-year old to ever enjoy some quality weed.

Is it illegal? sure, and so is speeding, double parking, and invading the privacy of the American people by listening in on their phone calls. But I don't see that getting much attention.