The open information is obtained without assetization, which is one of the common practices of the intelligence operation. It is available for the general public as well, but its analysis might create an important implication to the administration.
There are two critical meanings for this methodology, one of which is that it is absolutely a legal way to gather an information. There are many operations categorized as an illegal to obtain an intel through hacking, especially when it is conducted against their own people. Even if it is an attack against another country, its revelation might create a conflict later on.
For example, the CIA hacked a mobile phone of the German prime Merkel, which revelation has apparently lowered a trust of the United States. Their relationship is not hurt publicly, but this unacceptable action should have an influence at multiple occasions.
In the US law, the CIA’s wiretapping outside the country is not illegal, but it is a breach of the German law. However, the CIA’s illegal conduct at that time was hard to be prosecuted for the German government, as they were a critical part of the US foreign affairs.
On the other hand, the German government should monitor the CIA’s conduct more than before, which restricts a legal information gathering as well. Moreover, this failure might be capitalized by Germany to ask a concession against the US for other cases.
There is another merit for the open information that the intel is stabilized when availing the open source. The information from the intelligence asset is not necessarily stable, as they can access a critical information sometimes and not always, which is unstable in nature.
In the case of counterterrorism, it is not easy to gain an intel even when the intelligence holds assets in the terrorist organization. If they communicate often for a frequent update, their identity might be uncovered, which restricts the communication periodically. If this is the case, the intelligence has some difficulty in plotting a counterterrorism action with a full comprehension of the targeted organization.
This information gap can be made up by the open information. Even if the primary source is under dark, there is a possibility that the spy can reach the truth for a proper plan for the intelligence action.
If this is the case for another country, the agency can get a deeper implication just from the open source. However, there are a bunch of junk information including faked, hence it is required to have an ability to read between lines and to pick up a significant intel toward the truth.