[user104658]

Maybe it is to do with the level of actual physical threat, it's impossible to be sure as either way they obviously can't release too many details of their gathered intelligence without revealing how it was gathered and endangering sources, but I do have to say that I strongly suspect there are other motivations for the response. In part, at least.

That is, if the innocent Jewish community in European countries starts being openly attacked, the political situation will completely explode. Forget **** hitting the fan - we're talking about a massive tornado hitting a sewage treatment plant.

Muslims being threatened and attacked? Not such a problem, politically speaking. I'm sure there would be a response to any attack against any innocent group... But I'm skeptical that they would take the same sort of security precautions in response to intelligence about a potential threat.