How much caffeine is too much caffeine?

I'm sure there's a medical limit, but some people are so crazy for caffeine that they are pouring their Coca-Cola into their coffee. I'm fairly certain I've seen Coke actually offer up their own coffee drinks, but this is a completely different level of caffeine intake.

According to the video posted by Now This Food, people love the bitterness of the coffee mixing with the sweetness of the coke—and of course, the caffeine.

Some people are even adding milk. Have you ever tried the mix? I'm tempted to try it out but I also don't want to overload on caffeine.

If you decide to take the Coca-Coffee plunge, let me know how it goes.