Gold Farming Examples
Currency farmers are anomalies in the game world. For e.g. Gil sellers don't belong in Vana'diel, because real players pay dearly for their activities everyday at the auction house.
In a perfect world, there wouldn't be any troubles, but we don't live in a perfect world, so hence, the problem arises: IGE and other online companies sell Gil or Gold or Plat or whatever for all these various online games (FYI: Gil is the currency for Final Fantasy XI, and it will be what I will be using as an example).
These companies will of course need to HAVE the Gil in order to sell it, so they purchase the Gil from certain players. Now, if it were as simple as playing normally, then selling the gil they got every now and again, I don't think the problem would have arose. But that's not the case.
Final Fantasy - Archer's Ring

A fantastic example is Archer's Ring, which is dropped by a creature that spawns in Ordelle's Caves called the Stroper Chyme. From what I know, it spawns every twelve minutes at 2 spawn locations. The Archer's Ring is a Level 30 ring that gives +2 to both Accuracy and Ranged Accuracy. Because of Gil selling, this ring has seen its price increase ridiculously.
Why? Because gil sellers jack up the price, and rich high level players continue buying them because they need the rings and can afford it. It becomes a vicious cycle that leaves the weaker players and weekend casual gamers at the losing end.
Because of these high level players who can afford 600k-1,000,000 gil Archer Rings, they inevitably increase sniper ring costs, and force the other players like you and me to pay the exorbitant price when we need that sniper ring. We are not filthy rich, so that really sucks. It's not okay if someone tells me to "just deal with it", because it is just basically saying that it's okay for gil sellers to screw the economy up.
MMORPGs Are Supposed To Be Fun
Gil sellers spend most of their time camping high value items such as the Archer's Ring, and monopolize these spawn points. These organised syndicates destroy any chance of regular players getting rings, and the gil-sellers take full advantage of this fact to sell items at damn high rates.
On top of the screwed economy, these gil sellers severely affect the gameplay of MMORPGs too. If they played normally, it wouldn't have been so bad, but these players camp NON-STOP 24/7. The same group, too. These aren't just hardcore players who want the ring, these are people who DEPEND on getting that ring, and the Gil it sells for, for a paycheck.

Players who interfere or try to camp the spawn as well often face monsters that these gil sellers drag in from the surrounding areas just to make it harder for you to target the Chyme when it appears. That's a damn good way to spoil a game, and moreover, completely against the Final Fantasy XI Terms of Service.
The online companies try to cover their butts by not actually "hiring" these gil sellers. Instead, they claim that they merely act as independent contractors or middlemen. But it still means that they are buying the gil from these people and selling it to others. It's a huge industry that's completely and totally against the rules.
What's frustrating is that the game companies (e.g. Square-Enix, Blizzard), have not done anything to boot off these gil or gold sellers. They HAVE to know about the problem, and it's easy enough for them to find out who these people are, as well as to take action. So there's absolutely no excuse for the lack of action thus far.
That SUCKS.
