I'm getting thousands of JS button clicks per second on my site. What could be doing that and why?

I just set up a front end event tracking system using Segment.com and I found out that there are thousands of button clicks from one IP with a ~2 millisecond difference.

These are not HTTP requests, because events are only sent via JavaScript when the button is clicked. There's also an Apple Webkit user agent, so if it's a bot, it is a very sophisticated one that fully emulates browser behavior including JavaScript evaluation.

This is very weird. What could be doing that and why?

My guess is that it could be a browser malware that for some reason clicks website buttons every 2 milliseconds.