In order for them to pull this off, they will need to get on camera/audio. Therefore, watch for trouble around the MSM, and if you see something, start laughing or yelling “They are phonies” “They are plants” so that the camera or audio will pick it up.
They will tell the MSM where to point the cameras ahead of time.
You hit on something important, and to take it a step further: How about assigning a couple of people JUST to watch the media, so if an infiltrator steps up to the camera that person/people can immediately notify everyone else? Maybe those "watchers" could carry transcripts of Cavuto's show talking about plans to infiltrate/disrupt (and any other stuff that comes out beforehand like from leftie sites, etc) and hand it to the media and dare them to read it on camera...all while others are filming this as well. Just brainstorming.