Although the days when "gentlemen did not read other people’s letters" are long gone, they certainly read other people's postcards even back then.

While the tools of the trade comprise - and always comprised - both "hide and seek", covert and overt strategies, the impact and importance of OSINT obviously grow with the vast volumes of information openly available. This alone makes fostering an in-depth understanding and appreciation of the role OSINT can play especially for the collection in and benchmarking of an elaborate, all-source intelligence cycle critical. Of course, changing modes of collection will also affect the planning and direction, processing, analysis, production and dissemination of intelligence products in general.

I agree that improving intelligence means raising its reliability and, thus, credibility within its political and societal realm. As OSINT increases transparency, it also boosts accountability, for better or for worse. But just because more and more information is "open", does not at all mean that it is reliable. Information without proper judgment is without value. So in the end, the "game" is not becoming less risky, but much more intricate.

In a comprehensive intelligence analysis the quality of open source information (OSINF) has to be checked by using information from classified sources as well. Therefore, in practice, a final intelligence product must be classified in most cases to protect its sources. Even if OSINF/OSINT, in terms of quantity, may account for the largest share of information contained in intelligence products, it may not be as important in terms of quality and its relevance. Often a strategic advantage over the enemy can often only be achieved through information and intelligence from covert sources. In practice though, open sources are unfortunately not sufficiently exploited by intelligence services. Thus, there is also potential for achieving a strategic advantage through enhanced OSINT capabilities.

Sharing information with the public or other services is always risky for intelligence services. The fact that a certain information is openly accessible does not mean that everybody already knows about it. The knowledge where to find the information and how to interprete it right represents an extra capacity and effort which gives intelligence services an advantage over their enemies. If an information is of value, why would you want to share it with the public and your enemy then?

The business of intelligence services can be simply described as a 'Hide and Seek' game: Generating informational advantages over national enemies by concealing their own private information ('Hide') and by revealing the private information of the others ('Seek').

OSINF/OSINT certainly contributes much to the Seek strategy as there is a lot of relevant information openly accessible. It also includes the integration of external non-state experts in the intelligence analysis which represents both a chance and a challenge at the same time.

In terms of the Hide strategy, OSINF/OSINT can contribute to the credibility of intelligence services as it party increases their transparency which of course again represents an immense challenge. Credibility in the hands of intelligence services may then in turn also be used to deceive the public and the enemy. Finally, an increased transparency and credibility may mitigate popular outrage in the case of failures of the intelligence community.