"I ripped off a guy while playing the MMO Maple Story. So, there I was teleporting all around an area, grinding my butt off, when someone else pops in thinking they can kill alongside me. In Maple Story etiquette, kill stealing and item snatching is frowned upon, so if someone has already occupied a small area to grind the polite thing is to change to another channel and see if the same area there is empty. So I said "cc plz" and kept doing so... but it fell on deaf ears. The guy kept on stealing with a smile (literally, on his avatar). I then asked him "Would you please change the channel," to which he replied: "Deal with it".
"So, having enough of this I decided to teach him a lesson. I stopped grinding and asked this kill stealer if he has any need for 60% ATK scrolls at 8 million Mesos. ATK scrolls are extremely rare, consumable items that have a small chance of applying major buffs on a desired item. The 60% ones are worth around 8 million Mesos each. A lot. He says 'yes', he would like a scroll but he doesn't have enough. I ask how much, and he says he only has 5 million Mesos. After some outspoken deliberation I say 'ok', I can do that, and so we set up a trade window. Probably thinking his birthdays have come all at once, he puts in the money, I put in the scroll; just long enough for him to check the item. But I cancel quickly. He asks what happened, I say “Dunno”. So we begin to trade and, again, I quickly cancel. He asks again what happened, I say I'm not sure but the window keeps closing quickly. So we do this a few more times and every time I cancel quickly. He's losing patience and I fake losing patience as well. That's when I come up with the 'idea' that we both press confirm ASAP once the trade is up, before it has a chance to cancel (and funnily enough before we have a chance to check over the items being traded). So we do that and the trade goes through.
"What he doesn't know is that with this instant trade I put in a 10% ATK scroll instead, worth around just 20K Mesos. So the deal goes through, him still thinking he's getting a steal of a deal but instead is ripped off of all 5 million of his Mesos. He soon realises, but before he can go off on a tirade I say--with a smile--"Next time, change the channel", and teleport my butt out of there."