A couple of years ago Deadmau5 was at a signing in a record store in my city, I went along with the intention of handing him a CD with a couple of productions of mine on as a sort of demo.
I got there and he was doing a short live performance which I enjoyed for a while, and then everyone formed a line for him to sign things, which I joined.
I waited for about 20 minutes, people were chatting with him, getting pictures, the usual. When it came to me I said to him "I don't have anything for you to sign, but I would like to say that you're an inspiration to me, so I'd like to share with you some of the music I produced, which has been inspired by your productions".
I handed him the CD and he just looked at it in shock/confusion for a moment before saying "This is a signing, not a demo showcase. Either I sign this or you mail it to me."
I was taken aback by his rudeness and just shyly responded "I'd rather you keep it". He turned back to his tag along friends and said "can you believe this guy?" while chuckling.
His friends kind of awkwardly laughed along with him while giving me this awkward look as if to say "I'm so sorry".
I was so upset that I nearly punched the dude right there. I just walked away instead. I was so upset I felt ill.
I recognize that DJ's get handed demo CD's all the time and it must get annoying, but when I first started out producing I handed out a bunch of demos (some to people even more famous than Deadmau5) and I was always treated with respect.