It could be anything. I've had to deal with similar issues as this person has before.
I would be in a computer lab and there will be a couple deaf students talking and signing loudly. Everyone is distracted by these 2 students. So, when they are asked to be quiet... they immediately snap back "Hey! We're deaf! We can't hear ourselves being loud! We have an excuse to do whatever we're doing! So, fuck off!"
Whoa, what's with that attitude? Of course, this pissed off a lot of hearing students (including me, a deaf student).
Oh, there was one cute gal who was having a conversation with this guy. The issue of dating came up. Well, the guy bluntly told this cute gal... "I can't date you. I refuse to date you. You have hearing parents and don't sign 100% ASL!" Of course, this same guy used the same Deaf Pride and Deaf Culture attitude towards others to get what he wanted. He had a package for a deaf student. All he had was that student's name, but no address. He saw me and another student working in an office. He immediately walked in and started signing bluntly to my co-worker. "Hey, I have a package for this person. Do you know this person?" "Yes, I do." "Come on, hurry... I'm deaf and don't have all day to be treated like an idiot. Tell me where this person lives. Come on!" This made my co-worker very awkward, but I calmly interrupted telling her that she didn't have to tell him. He then looked at me, "Hey, it's none of your business. Shut up! You have no respect for us deaf people!" He then stormed out. (I could give you more stories of how he manipulated the deaf community with his "Deaf Pride" and "Deaf Culture" stuff.) He basically pissed everyone off.
So, I can understand where this guy is coming from. What he did may have been harsh, but he was just venting out his feelings online. After all, isn't that something many of you do in your blogs?