I wouldn't know, I know somebody posted a gay screenshot on NB which was taken down. If what you say is true then that would mean it was nost definitely a fake image.
Thanks
All of the chans are 2-channel boards. Posting is done anonymously and there is a name field that can be filled out, but this is generally frowned upon in Chan culture. "Name-fagging" is something one only does after having earned a reason to be a namefag - which is a very small portion of the people there; and even those who have earned such regards often lose them. It isn't about who posts something, it is about what is posted.
Anyone can go onto one of the chans and fill out the name field to be anything they want, then make a post. Chan culture is also heavily anti-censorship, to such an extent that people will leave boards whose owners enact censorship. The only posts that are removed by the site hosting service are those which violate fair use laws or illegal forms of pornography. As such, it is not uncommon to see people respond to posts they do not like, or think are stupid, with particularly vulgar forms of pornography accompanied with language that typically results in bans on most forums. People who display indications of being new to the chans, newfags, are generally met with a trial by fire. Signs of being new include concerns over the language people are using toward each other and the content of pictures they may be posting - exceptions allowed for pictures where women have tattoos or other indications of being slaves.
In the case of what happened to yours - it could be that someone just found a random post on one of the chans and edited it to include your name; or someone could have actually made such a post using your name in the field.