Many ISPs have already adopted the controversial practice of serving advertisements when a customer tries to browse to a Web site that does not exist. But a growing number of providers also are serving ad-filled pages when customers request a subdomain of a Web site that does not exist, such as something.example.com. This practice, which experts say potentially introduces new copyright violation claims, also potentially introduces security threats when ISPs outsource the ad-serving process to third parties.
I’ve never knew this was happening, but it’s not surprising at all
I just hope all of you have adblock…
Via washington post