Like a stalker, I sit out your house everyday. I never move and sit in the same spot. I wave a flag and have a pretty important job to do. I often eat light objects but also things with more bulk. What i eat, I do not consume, and what goes in my mouth comes back out of it. You can get information out of me, however i don't speak to you. Sometimes you do not like what I have to offer you. I am numbered among many friends. What am I?