I can't seem to find a previous thread on this topic so hopefully I'm not creating a non-necessary new thread Nomad.

I was on a LHR-YYC flight this past weekend in J and became extremely suspicious of a few pax sitting in J. I was sitting next to the one pax who first caught my attention as he had his own water bottle (not the small bottle of Dasani that is given in J) and I also noticed he had a pen (another banned carry-on this past weekend from LHR). He was late 30ish, well dressed and kept a light dress jacket on the entire flight. He seemed very polite with the flight crew, but was very stern and serious looking throughout the flight. I was already on edge enough with the security situation the past week without having to see the water bottle and pen, but then he would also occasionally get up and speak very discreetly, quietly, and suspiciously to two pax two rows ahead. Suspiciously meaning he would usually slightly cover his hand over his mouth so his voice wouldn't carry or so no one could see what he was saying. One of these men he spoke to looked of middle-eastern descent, which only added to the worst-case scenarios running through my head.

After a couple hours with the anxiety brewing, I went up to the galley and started a conversation with one of the flight attendants. I finally mentioned my concern with the three suspicious gentlemen. The flight attendant told me not to worry that these men were frequent flyers with AC and travelling together "on business". This at least eased the anxiety and made me wonder if perhaps the gentleman beside me was an air marshall.

The rest of the flight went without incident, but in the jetway after deplaning the flight attendant I spoke to rushed out to me, pulled me aside and asked me how I had become so suspicious of these men. I told him about my concerns and he told me that all three were in fact sky marshalls and thanked me for raising my suspicions to him.

So I have several questions:
1) Is it normal to have 3 or more sky marshalls on an AC overseas flight or is this just due to the recent events in the UK?
2) Wouldn’t one think that sky marshalls would try to be as discreet as possible to not bring attention to themselves and especially not do things that would make them look like potential terrorists rather than someone protecting us on the flight? If I notice someone like this then a potential terrorist surely would.
3) Are all the flight crew aware of who the marshalls are on a flight?
4) Has anyone had any other experiences with sky marshalls on board their flights?