Don't leave a plate out with food on it and walk away with this cat nearby. He'll be up on the chair in no time, sniffing and perhaps stealing your food in a moments notice.
SWIPER NO SWIPING!
I found he doesn't like vegetables. So if I ever want him to go somewhere else and stare from a distance, I simply offer him some greens or something citricy. He prefers his manufactured kibbles.
There are up to 60 million feral cats in the United States alone.