I'm assuming that the "monitoring" notice you got was the same one I found at the YPG website. This is pretty much "boilerplate" that you'll find at any US Department of Defense website, and probably shouldn't be of too much concern.

The same, or very similar, warnings are posted on large signs at the entrances to most US military (or other Department of Defense) facilities. In normal times, very little monitoring is probably done - it's just that it can be, and you need to be aware of it before entering. I suspect that they may be looking a little more closely now, but probably only for "subversive content" or attempts to interfere with the site. - I hope you don't qualify there.

The only overt application of these monitoring rules I've seen was when Boeing (as a DoD contractor) used them to (without warrant) break into cars in their parking lot to confiscate phony parking stickers a few years ago in Seattle.

John