The spy has originally targeted a public officer as an asset to gain a secretive information of other countries or it has been necessary to acquire the bureaucrats and politicians for their further operation, which includes intelligence officers.
At the same time, members of criminal organizations are essential targets. If acquiring assets within the antigovernment organization or terrorist group, the intelligence can capture their future action. In this sense, those targets are basically the same as ones in the counterpart government, as all of them are political in any way.
The asset within the ordinary crime organization is categorized a little differently. For example, the spy has hired many assets within the network of mafia and drug dealers, some of those are connected to the antigovernment activities, but not necessarily.
This target range of the intelligence depends on the operational range of each spy organization. The CIA has a team just targeting crime organizations, which is a result of their budgeting capability and political request. If approved like this, they have an enough money to acquire some of the targeted members as an asset.
This target can be expanded to the different direction. If their true target is improbable to acquire as an asset, the spy might hire another who can access to this individual. For example, the spy can affect an administrative policy through academics who is targeted as an asset of the second derivative. Some of them have quite often contacted with outside world, hence they are one of the easy targets for this assetization.
The media is another category which is quite accessible to the politician in charge, as the journalist sometimes has a deeper insider information. Or, the spouse is also another target to be turned, all of those are ways to expand the spy network.
The spy target has been expanded more to the economic relations since the 1990s. The intelligence has been less required as the cold war ended and they were asked to expand their interest on the economic issue, which is why more ordinary people have become subjects of the spy antipersonnel operation. That was the only option to take in those days.
As a result, the asset network also has proceeded to the normal people. It is originally meant to take an economic intel, though this network has self-determined to acquire more ordinary people into their network.
There is no way for them to access a critical information, but they can be availed for the spy operation, hence their network is expanded.