> "It may be isolated incidents"

Yes, "it may". German agencies are famous for "isolated incidents". It's only a matter of definition what's to be called "isolated".

Those isolated incidents reach back even to the "Operation Gehlen"[0], the predecessor of the BND which was founded in 1946. One could say that the history of German agencies is the history of isolated incidents. While this may hold true for intelligence agencies all over the world, the historic ties leave a very bad taste regarding right-wing-terror in Germany. The "National Socialist Underground" (NSU)[1] was only the tip of the iceberg.

[0] https://en.wikipedia.org/wiki/Gehlen_Organization [1] https://en.wikipedia.org/wiki/National_Socialist_Underground