Short version goes thusly: A warlock on Aman'thul stated that he repeatedly petitioned the support team regarding his missing artisan riding skill - 5000g down the pan. Cue indignant nerdrage, been petitioning for months, gonna cancel all three of my accounts, Blizzard sux etc. The original post has since vanished from the thread, but it's quoted for prosperity a little while down the first page.
A little further down the first page, GM Auryck had been diligently investigating the situation and gave his findings.
With subtly hilarious results
So the moral of the story is that the GMs have access to a lot more logs than one would assume. Granted, they're not tracking every single transaction and every line of guild chat, but if challenged in a public forum to investigate your claim thoroughly they will do so; and since you've made the topic public, the result is likewise there for all to see.
Sleep tight, Lurkers.