Akismet is the anti-spam service which is made for WordPress by Automattic, the company which owns WordPress.com.
The service was launched on October 25, 2005, and was one of the very first monetization strategies put in place by WP founder Matt Mullenweg in the then fledgling Automattic business.
Akismet is free, but has paid tiers for “commercial use” starting at $5 per month, with higher packages for increased usage.
Bearing in mind the weight of spam comments which took place – at least at one time – having some kind of comment spam removal plugin in place is vital for WordPress webmasters. Akisment is a good option.
European Privacy Concerns – Germany & the EU
It should be noted that there have been some privacy concerns raised in countries like Germany, over the fact comment data (containing personal data) is sent and to and processed by datacenters outside of the European Union (EU).