Blizzard is continuing to put pressure on individuals and services in an attempt to stop what it believes is illegal activity in MMO World of Warcraft.The company has already seen success, most recently by shutting down private WoW server provider Scapegaming as well as being awarded $85.4 million in damages.Now the attention has turned to gold sellers. Blizzard already blocks WoW accounts when it detects a gold seller, but that isn’t enough to keep them away. So instead, Blizzard is trying to cut off their revenue.While a number of online payment services are used by sellers to allow money transfers, PayPal is one of the largest. Blizzard submitted a complaint along with account details to PayPal stating that intellectual property violations were being carried out by customers of its service in this regard.PayPal responded by sending the following notice to anyone using its service for such activity:You were reported to PayPal as an Intellectual Properties violation by Blizzard Entertainment Inc. for the sale of World of Warcraft Merchandise.If you feel your sales do not infringe upon the intellectual property rights of the Reporting Party, please complette the attached Objection to Infringement Report by January 21, 2011.The completed form should be faxed to the attention of the Acceptable Use Policy Department at [number removed] or emailed to [email removed].Should you choose not to object to the report, you will be required to remove all World of Warcraft Merchandise from the website [url removed] in order to comply with the Acceptable Use Policy. Read more at WoW InsiderMatthew’s OpinionBy targeting the service that allows gold sellers to be paid, Blizzard is really hitting them where it hurts. They can always switch to another payment service, but PayPal is by far the most used and therefore the most likely WoW players will have access to and funds in.Using PayPal to cut off gold sellers also has another advantage. Blizzard can only try and prosecute these companies or individuals otherwise, and many of them are not in the U.S. making it difficult to do. PayPal is worldwide and can cut off users without the need to use the law on a per country basis. If it works, Blizzard could drastically cut the number of gold sellers on its servers.