http://bentasker.i2p/posts/blog/opinion/users-are-the-casualty-in-wordpress-v-wpe.html
Matt (and Automattic) could not have been unaware of this, given that they were early investors in WP Engine (in fact, WP Engine were even the launch partner for Automattic's "VIP Support for Web Hosts" program). So, Matt has likely been aware of the "objectionable" use for at least 13 years with no apparent attempt at enforcement.