Football agents. They started out as innocent representation for players, helping to protect the best interests of an individuals more equipped to run about on a pitch than sit around a negotiating table and thrash out contracts.
Fewer than 30 years ago, agents weren't exactly commonplace. Players in England often sought advice and help from the PFA when it came to transfers - Roy Keane didn't have an agent until 1993 when he was on the verge of leaving Nottingham Forest for Manchester United. Even then it was a referral from an international colleague to a trusted lawyer who dealt largely with property.
Keane was also seeking assistance from the PFA at the same time, sceptical about the whole still relatively new idea of 'agents'. He later noted in his 2002 autobiography, "From what I had observed, it was clear that players' footballing fortunes were not agents' prime consideration."
Today, there are thousands of licensed agents working in Europe alone, with many thousands more around the world. Now, these agents effectively run the whole transfer market, forcing it in whatever direction they want, and their grip is only growing tighter with each passing winter or summer window.
Agents could once be accused of greed if they demanded bigger wages from a club for a single client, always thinking about that 10%. But now there is so much more to it, especially when one considers that, between them, a small group of so-called super agents represent most of the top players in the world.
These people can build entire teams, they can also tear them apart. They can be a club's best friend or their worst nightmare, and you're risking an awful lot if you get on the wrong side of one.
Jorge Mendes has brokered well over £1billion worth of transfer deals in his career and essentially gave Monaco a new team in 2013 when he was responsible for taking Radamel Falcao, James Rodriguez, Joao Moutinho and Ricardo Carvalho to the principality club suddenly cash rich after an injection of Russian investment.
He has had strong ties to Valencia, with a number of clients at the Mestalla, while his dealings with Real Madrid are also very well known. Having grown flirtatious with Manchester United, that is only going to increase in the coming years - a product of Ed Woodward's search for his own Old Trafford Galacticos, and the arrival of Jose Mourinho, one of Mendes' biggest clients.
Falcao's surprise move to Chelsea last year is believed to have been the result of a personal favour to Mendes, so how long before United sign someone they don't need or want just to as a gesture of goodwill to keep him happy?
The temporary upside for United is that while Mourinho is in charge, Mendes is unlikely to actively try and take players away. Whether they are his own clients like David de Gea, or if he's acting as a broker or intermediary on behalf of another club looking for certain players.
It's no coincidence that the latest rumours of de Gea's proposed move to Real Madrid are of the deal being dead. The player was never actively pushing for it to happen, although he would have happily accepted, but crucially now Mendes doesn't want it to happen, so it won't. That goes to shows just how convoluted and fickle the whole agent paradigm is.
To move on slightly, the practice has also allowed a number of clubs to become a little lazy in their recruitment. Some simply don't need to scout as extensively as they might have done to unearth gems because agents are constantly offering them various clients. It rarely works out for the best, especially when you think of which Premier League side recruited best last season - Leicester City.
Where modern agents excel (not in a positive sense) is using the 24 hours news society to their advantage. How many times have we heard Mino Raiola, agent to Zlatan Ibrahimovic, Paul Pogba, Romelu Lukaku, Henrikh Mkhitaryan and others, make often meaningless statements to reporters that will form the basis of a new headline? Too many to count is the answer.
Usually, it's 'fails to rule out move', or 'drops hint'. What they're after is the publicity to keep the subject of their client's next move in the news and put pressure on clubs.
Disgruntled fans sick of reading transfer rumours that never become reality like to think that journalists sit in front of a computer screen pulling random names out of thin air and splicing them together in 200-300 words. A lot of the time, those rumours you hate so much are leaked by agents. It's not pretty and it verges on sinister, but it's an effective tactic for them.
In just 30 years, agents have gone from novel rarity to the most powerful people in football. They control the players, they drive the transfer market, they control the clubs. This is now the norm and it's actually quite unsettling.
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