Not very kosher, Amar'e. Now, granted, this dude totally trolled Stoudemire with a nonsensical taunt basically out of left field ("you better come back a lot stronger and quicker to make up for this past season mannnnnn deadasss!!!"), but still. At this point Amar'e has surely heard worse—I mean, I don't even know what a "deadasss" is—so it's a little surprising that this prompted such an ugly response.
The screenshot above is from a direct message Amar'e sent to the fan and looks legitimate. I did ask him to send me the email notification he got for the direct message, but I'm still waiting for it. I'll update if and when I receive it.
If Amar'e did send the direct message it's just another in a long line of examples of the times having changed a long time ago for athletes and celebrities. Their actions have been scrutinized more and more with things like Twitter and facebook making it incredibly easy for any asshole with a twitter account trying to get a rise out of them. It seems some are still trying to catch up with not only the times, but also ways of popping off at folks without resorting to stupid "insults" like "fag."
Update June 24, 8:04 a.m.: Amar'e has apologized via direct message.