The first cranky riddle.

Since I am so fond of puzzles, games, riddles and conundrums, I thought I should introduce one to my readers. What you have to do is guess what person this open Coke can represents. I'l give you some clues. It's not someone very bright or honest. This person has a major effect on your life, mostly negative. And unless someone slips this person a poisoned Coke, we won't see the end of them soon.