Man behind

The man behind me has been doing nothing for the past six hours. He is just sticking to his seat. I havent heard the cackle of his keyboard even once. He has opened a blank Word file and its there since 1 pm. He has been quitely listening in when I have been talking to my guests or colleagues all day today and he is sitting sideways so my computer screen is in his full sight. He is getting on my nerves. cant write anything else until I get rid of him.