A discussion came up on a anime con Facebook site about cosplayers ,females and males, being asked embarrassing questions or commits directed at them about their costume or why they are doing something like that.
One story I had seen was a group acting as news or documentary crew approaching someone and ask questions sexual or other wise to the cosplayer. Doing things that made them uncomfortable. Filming their chest or other areas. One female reported this group to the anime con group but said nothing was done to stop them or remove them from the con.
I have heard of incidents where coplayers are asked to pose in some way in a manner that could be uncomfortable to how they felt about it. Even having the harasser pose in some way, like without their shirt.
Physical touching or even assaulting a cosplayer. At one anime con I know of, a young man wearing a box over them as a costume was assaulted by other con attendees who were caught arrested and banned from the con for life.
Now in this discussion was the idea for those who are against harassment, bully, assault of cosplayers to wear purple ribbons with the words BACK UP on them on their con badges to be willing to step in to help confront a harasser. This could be another attendee or a con volunteer or staffer maybe personnel working for the building where the con is being held.
It may not always happen at a anime con but also comic cons or anywhere people will cosplay.
As a con staffer I have to watch for problems and step in to control the situation. I would also hope that other attendees would come and find a staffer or step in until a staffer gets there to help someone in need.