If you post to the LFG Tool, your games will be visible to all players. By their very nature, forum posts and games posted to the LFG Tool are public, as they take place in the public areas of our site. The blocking feature is a way for you to avoid players on our forums and to prevent them from private messaging you. So yes, they would inevitably realize you blocked them, but as it stands now if a user is blocked and they try to message you they get an error message stating that they are blocked. That being said, all community areas of our site are governed and protected by our Code of Conduct and Terms of Service . If you are concerned or are having trouble with a user you are welcome to email us at <a href="mailto:team@roll20.net" rel="nofollow">team@roll20.net</a> with details so we can support you.