Additionally, I think you'll find I'm acutely aware of how non-anonymous my posts are, and have always been relatively tame in my posting history on all sights.
It's not the acting out that will effect the professional careers of the people. It's the fact they have the hobby at all which is an issue professionally, especially in this job market.
Which is going to be hired most places: 29 yr old who has a reasonably good background and hobbies include gaming, reading and music, or a 29 yr old who has a reasonably good background and hobbies include reading and music? For many fields, the second is a more attractive candidate, and not for completely irrational reasons.