How to handle crazy visitors that use up your bandwidth?

I noticed one of my visitors went crazy. Looking at the logs it started like a normal visitor coming from google but then all of a sudden the page and the favicon was requested continuously for about 4 minutes which resulted in thousands of request and 22 MB bandwidth used up. Not sure if I'm overreacting because 22 MB doesn't sound that much but it's about half of last month's total bandwidth usage for that site.

I'm not sure what happened really. Did he do it on purpose? Holding F5 or was it some kind of bot? Could it have been a technical problem? I don't know and I don't expect you to know. The referer for each page request was "https://www.google.se/" if that means anything. The IP is from the country that the website is targeting so it is not just some random bot from the other side of the world.

I'm not sure how or if I should take action to prevent this from happening. I could of course ban the IP manually but that doesn't really stop future "attacks" from different IPs and maybe this was just a one time thing. I would be more interested in some kind of autoban feature that automatically bans IPs that makes too many requests in a short time. Does CPanel has something like this built in?

Have you noticed something similar on your site(s)? What actions did you take to prevent it?