The way it goes down is this:
Members of the intelligence community are patient. Very very patient indeed.
They will build up a dossier of all of your dirty little secrets over a period of years; decades even. They will wait as long as it takes for you to get into a position of power; until they really need something from you, and then, why then they have a nice big fat file waiting for them in the archives, they will come to you and ask you for a "favour".
It could be to hand over some information, perhaps your organization's "red lines" in a negotiation; or the price your company is willing to pay in a takeover bid. It could be to do somebody else a favour, help them out with some insider information, or give them a job. Perhaps, they will ask you to screw somebody over, deny them a job, block them from a position, and so on. Easy for you to do, no skin off your nose; particularly in comparison to the alternative: the awkward conversations you could be having with your spouse that evening, or the IRS later in the week.
In this way, positions of influence get filled with puppets and cronies, and their network of influence and power grows and grows. Who needs money when you have all these little bits of leverage, all these people who will do things for you, individually inconsequential, but collectively ... world changing.
Indeed, the financial services sector .. so dependent on (and so vulnerable to) hard-to-trace insider information, I would not be totally surprised if that sector is completely in thrall to the organization that is dominant in the information-warfare arena.
An addiction to information? No. An addiction to power, fuelled by information. That is why they gotta collect it all.