Illustrator Ehime Mikan, who is a company employee by day and part-time illustrator by night, took to Twitter, asking fellow Comiket attendees to be mindful of the erotic bags they get at the show. Ehime Mikan pointed out that at the station and surrounding the convention center, there were regular folks—kids, too— who don't need to see the imagery on the bags. Think of this as common courtesy for nerds!
Instead, it might be a good idea to bring a more discreet bag to put your not so discreet spoils into.
To get an idea of what kind of imagery is featured, have a look at some of Comiket bags from 2011's winter Comic Market. Some of the far more extreme ones can be seen in the link below.
Comiket Bags Here [Akiba Blog]