Sorry if I didn’t explain correctly. Holding the camera is not considered terrorism. As I said is legal (but sharing the recording is not), but the police can tell you to stop recording and take your device, also legal. Once they’re not being recorded, if they beat you up (high probability specially if there’s not many people around) they’ll justify it by saying you attacked them first, which is the part that can be considered terrorism.

I haven’t seen, personally, this happening for recording them, but I have for other things like trying to stand by your rights during a search, intervening when they where harassing someone, asking for their badge number (legally should be visible, and they have to tell you if not. But usually doesn’t end up well)… This is Spain, but I’ve heard stories about the Italian, French, German, many east European countries’… polices and they doesn’t seem much better.