Remember about 16 months ago when they merged AH's? I do. Before the merge I had a successful gemcutting operation going on the Horde side of a mostly Alliance server. I was making 30-40k/wk when most people never dreamed of having 100k gold. Life was good.
Then they merged our AH's in the pre-patch. I was using TSM to cancel and repost aggressively. Prices dropped, but I was doing great volume. About 2 days after the merge "Gemgirl" contacted me. Gemgirl was a new lvl 1 alt tied to someone who thought they controlled the gem market on the server. The link below is most of the mails I received from her. One or two early on were deleted before I realized I should be saving them, and you have to fill in my responses. Basically I went from "Who's this overbearing person, I'll listen and be polite," to just ignoring her. The last one came about 2 days before WoD dropped. On a side note, I'm pretty sure Gemgirl was a dude who had a thing for playing female toons and overdoing the "I'm a girl, give me attention" thing based on his interactions in trade chat on the Alliance side.
The best part of it for me was that after being annoying and a pain in the rear, this person was apparently manually cancelling and reposting multiple times a day to counter what I was doing in 5min with TSM. Probably frothing at the mount angry with me and I was barely aware other than "Oh, I've been undercut. Time to go repost." Also, to fill in the blanks just a little, at some point in there (s)he apparently had started to buy out all the uncut gems and even all of the ore on the AH below insane prices. Since I mined my own ore most of the time I was hardly aware of it. Also, despite threats to report me, I was never contacted by Blizzard for any sort of harassment.
Edit2: This person has since deleted that alt so please don't go witchhunting him or her. I did a quick search on Wow and there are quite a few "Gemgirls" out there. None of them are on the realm in question.