I had numerous attacks on one of my sites, thousands of strange coded page requests and efforts to break in.
(It looked like China and Ukraine hackers have joined forces to hack into this lousy blog).
I have installed the plugin and the page requests and strange activity decreased totally.
The interface is simple (for a non tech guy like me) and is explained in simple English and not in programmers code jargon.
Everything now works great and I feel more secure.

The best part is that on the other side of this plugin there are REAL PEOPLE I could communicate with.