Signs are banned at otakon this year. Taken from the official Otakon site:
Signs at Otakon
While we understand the appeal of signs as ice-breakers and conversation starters, there have been too many complaints from our members about offensive content or signs that amount to little more than panhandling.
No signs are permitted except for those signs that are an established part of a costume. (The sign must be part of the standard "look" of the character, such as the sign carried by Genma the panda.)
Those members wishing to post notices or find other people should use the bulletin boards provided. Please note that signs asking for food, money, hugs, etc. are considered panhandling by the Baltimore Police department, and signs offering to exchange any sort of sexual favor (kisses, hugs, glomps, etc.) are considered solicitation. Signs with offensive content are not allowed regardless of whether they are "in character."
Signs in violation of this policy will be confiscated. Repeat offenders will be considered in violation of the disruptive behavior policy.
Please note that this policy applies to all types of signs, regardless of construction. Otakon staff decisions regarding signs are final.