There is a number of pictures in the 'Anon' tag with Japanese men with mask that usually have the Kanji 'Sin' written on it. Eg. post #574554
Meanwhile, there is another picture that has an actual Anon, with a green mask/face that has a '?' symbol. Although it could also be a 'No Picture Found'. Eg. post #385819
I think that the difference between these two different type of 'Anon' should be clear.
Anon in '4chan' would be a indication of the anonymous legion, whether they are sadists, perverts or down-right insane, they do not have a identity.
While 'Sin Mask' (Don't know actual name) is a Japanese meme, where it's anonymous perverted men, all being horny over a certain character, or just the general cuteness.
I do not think that 2ch would agree that the majority of anonymous posters in that site are downright perverted people with 'Sin' written on their face.
Request of seperate tags, 'sin_mask' (Or the official name) for the Japanese men, and 'Anon_(4chan)' or just 'Anon' for anonymous.
And also a request of who the 'Sin mask' people actually are. Whether they are actually indicated as VIPPERs from 2ch, or just a meme of men who love certain characters to the point of perversion.
Updated by Solamarle