Actually it would make a certain amount of sense that the Federation President was in total control of S31, and they being a paranoid dirty trick organization they spy on their own boss.
As for Sloan, as a field agent/flunky he probably doesn't know who his boss really is, and is under the false impression that S31 is separate from the Federation's governance. His head full of (mostly) disinformation in case of capture.
This would likely be exactly the sort of model such an organisation would use. Why would they sow such a level of disinformation externally but have the one character we see on screen (at that point) totally informed?
Even the most legitimate intelligence agencies compartmentalise their information bases, with their peers often operating like terrorist cells, so why on earth would Sloan be so well informed as to let us take his perspective as gospel?
There is no evidence whatsoever that Section 31 answers to the Federation President; the canon is very clear that they answer to no one but themselves. Furthermore, "Extreme Measures" establishes very clearly that Sloan is very high up within Section 31, having access to all sorts of Section 31 operations, including their deployments on Qo'noS and their spy in former President Jaresh-Inyo's cabinet.
I also picture it as a 'black' organization under the CIA-equivalent umbrella.
If it's not sanctioned by the government then its just a criminal organization.
Exactly.
Because anyone or thing not sanctioned by a government is automatically a criminal organization?
No, but any organization that puts itself above the law and unaccountable to the democratic state,
is.
Section 31 is to Starfleet as Hydra is to SHIELD.
My usual take on S31 is that it's essentially a group of Federation private citizens who on occasion take matters (but not the law) into their own hands.
Your take is flatly contradicted by the canon.
If you usurp the jurisdiction of the executive you are a criminal organisation. Powers of life and death are solely within the gift of the executive to delegate. If S31 hasn't this authorisation, they are formally a gang of murderers and terrorists.
This.
I don't buy the idea that Section 31 isn't sanctioned by the Federation in some way. They are too well connected and have access to too much equipment to be what people seem to think they are.
Having high-powered agents loyal to your criminal conspiracy helps.
Comparison: When United States Marine Corps Colonel Oliver North and his associates in the Reagan administration were conspiring to sell arms to the Iranians in order to fund the Contras in Nicaragua, were they acting as "the government?" Or were they acting as a criminal conspiracy within the government, utilizing governmental resources illegally?
Part of out problem with how we perceive Section 31 is that almost all out interaction with the organization in Deep Space Nine are via Bashir, who is a Lieutenant and a Doctor. Both of which are not generally cleared for information on top secret matters nor information on the more hidden parts of Starfleet Intelligence. That is our point of view entry for Section 31 and Sloan never really answers Bashir's questions. Even if it would benefit Sloan into getting Bashir's aid, I doubt he'd give up what section of the government they operate out of simply because that is need to know and Bashir, who is clearly against the concept of there being a Section 31, doesn't need to know.
Look at "Inquisition" agent. Sloan's goal is to persuade Bashir to join Section 31. Bashir refuses to join not so much because he is against the idea of espionage and black ops, as because he is against the idea of an organization that puts itself above the law and makes itself unaccountable to the democratic state. If Section 31 were actually a legitimate part of the Federation government, it would be irrational for Sloan not to disclose this to Bashir, because doing so would allow him to achieve his objective.
And the actions seen in the episode In The Pale Moonllight, would you describe the DS9 senior officers (and Garak) as "a gang of murderers and terrorists?"
No. But there is a key difference: Sisko reports his and Garak's actions to his superiors in the Federation Starfleet. Now, what they did was a violation of both Federation, Bajoran, and interstellar law. But the simple fact remains that whatever else you might say about them, Sisko makes himself and Garak accountable to the democratic state in the person of his superiors at Starfleet.
In terms of a basic concept it is comparable, it's individuals stepping forward and doing something without first seeking permission.
There is a huge difference between doing something to protect yourself without "seeking permission," and creating an organization that regards itself and its members as above the law at all times and unaccountable to the democratic state.
They are protecting their families (Sloan spoke of his family), protecting their community, and protecting the Federation as a whole.
Interestingly, out of six Section 31 operations we have seen them undertake canonically, exactly
one operation actually served to protect the Federation in a competent manner.
The first time we see a Section 31 operation (going by release dates of episodes/films), we see Section 31 abduct and torture Julian Bashir in 2374 in order to "test" him for loyalty, to persuade him to join Section 31. They fail to do so. ("Inquisition")
The second time we see a Section 31 operation in 2375 ("
Inter Arma Enim Silent Leges"), they conspire with Romulan Tal Shiar Chair Koval to have Romulan Senator Cretek framed for treason and executed, and Koval placed on the powerful Continuing Committee, nominally because Koval is loyal to Section 31 and Cretek as a Romulan patriot might one day adopt an anti-Federation political stance. Setting aside the absurdity of the idea that the Chair of the Tal Shiar could be trusted to be loyal to Section 31, the operation is rendered moot when the entire Romulan Senate is assassinated just four years later by Shinzon of Remus, who seizes the Romulan government. Their purported agent Koval is clearly dead.
The third Section 31 operation we see is their attempt to exterminate the Founders of the Dominion by use of a morphogenic virus, which they deployed in 2372; this was established in the Final Chapters arc, particularly "Extreme Measures." This operation fails, thanks to Dr. Bashir being able to fish the cure out of the mind of Section 31 agent Sloan. Furthermore, this operation had the effect of producing the
opposite result from what Section 31 intended even before it was thwarted; the Founders' existential malaise convinced them to attempt to exterminate the Cardassian species and to fight to hold Cardassia from the Allies in a pyrrhic victory that would have cost many millions, if not billions, of sentient lives. Fortunately, the Founders relented upon being given a curse for the virus. Had the cure not been offered, God only knows how much longer the war would have dragged on and if the Cardassian species would have survived.
The fourth Section 31 operation we see ("Divergence/Affliction"), in 2154, sees Section 31 allow the Klingon Defense Force to abduct the Denobulan national Phlox from Earth so that he can be coerced into developing a treatment for the Klingon Augment virus that is spreading throughout the empire. Their actions nearly result in the destruction of United Earth's two most important starships,
Enterprise NX-02 and
Columbia NX-02, and
do result in widespread anger and resentment against Earth for the Augment virus that creates the
QuchHa' (ridgeless Klingons). Oddly enough, they didn't think to simply request Phlox intervene consensually.
The fifth Section 31 operation we see later that same year ("Terra Prime") has them giving key info to the crew of
Enterprise NX-01 in order to transport a landing party to the hijacked verteron array on Mars and defeat the Human supremacist terrorist organization known as Terra Prime. This operation succeeds in its objectives.
The sixth Section 31 operation we have seen featured in 2159 of the Kelvin Timeline. In that year, it was revealed that Section 31 had undertaken a complex operation to revive Khan Noonien Sighn and the exiled Augments he led, in order to provoke the Klingon Empire into launching a war against the Federation; the head of Section 31, Alexander Marcus, who had become head of Starfleet Command, would then lead the Federation in war against the Klingons. They had also concealed a shipyards facility from the rest of the Federation and built a powerful starship called the
Vengeance. Their plan failed when Marcus proved unable to control Khan and to prevent Captain Kirk from uncovering the true nature of his plan to incite a war. It resulted in the exposure and hijacking of the
Vengeance by Khan, Marcus's death, the near-destruction of the USS
Enterprise, and the destruction of both the
Vengeance and most of downtown San Francisco when it crashed into the city. God only knows how many thousands of innocent civilians Section 31 got killed -- or how many billions more they would have killed in their Federation/Klingon war.
Of six operations, exactly
one actually served to protect the Federation and was handled competently. The rest of them failed to achieve their objectives -- and would have made the Federation vastly weaker and less safe if they hadn't been thwarted by officers of the legitimate Starfleet.