Change your login url for http://example.com/login and stop login brute force attempts.
This is a great way to limit bots trying to brute force your login (trying to guess your login and password). Of course, the new urls are easier to remember too. The plugin is small, fast, and does not create new security vulnerabilities like some other plugins I've seen.
No settings: activate, it works.
Also remember: the use of this plugin does NOT exempt you to use a strong password. Moreover, never use "admin" as login, this is the first attempt for bots.
Yep! The plugin must be activated from your network.