If the vitriol regarding FR24 is aimed at my post #3424, then I am rather surprised. As others have pointed out, the website and all the information it contains is freely available to anyone with an internet connection. The latest Fr24 blog update has an entry highlighting NATO airborne activity in eastern Europe with examples of some of the aircraft types involved.
BTW, if the comments were aimed at my post I should add that I am not a 'spotter', but having said that, why the denigration of a hobby/pastime enjoyed by many?
I am ex-RAF (the 'ex' bit occurring a long time ago), have an on-going mild interest in aviation related activities including (obviously) that of the military persuasion.
The question I posed in all innocence was regarding overflights or otherwise of a fellow NATO member. Seemed a fair question to me.