... people are actually more sensitive to group norms when they are less identifiable to others .
That's interesting, but not very surprising. If you think about any popular social media site, they all have unique "cultures" about them. These "cultures" are only identifiable because majority of active users will conform to them. 4chan, as a site that provides extensive anonymity, has users who adhere to a very particular and strict culture. New, interested users often try and struggle to understand the rules of that culture.
Of course, that's just one example.