Anti-spam comment system.
https://wordpress.org/plugins/anti-spam/
Widgets · WordPress Plugins
Get access to data on 119,288 websites that are Anti-spam for WordPress Customers. We know of 30,780 live websites using Anti-spam for WordPress and an additional 88,508 sites that used Anti-spam for WordPress historically and 16,277 websites in the United States.
Get a list of 119,288 websites using Anti-spam for WordPress which includes location information, hosting data, contact details, 30,780 currently live websites and an additional 16,168 domains that redirect to sites in this list. 88,508 sites that used this technology previously and 16,277 websites in the United States currently using Anti-spam for WordPress.