How to Know If Someone Blocks You on Twitter
The social media website Twitter differs from others like Facebook and MySpace in that only two possible means of communicating with other users exist: "tweets," or short messages you send out to your entire friend network; or direct messages you send to individuals. Twitter permits users to block one another, which prohibits all forms of communication between them. If you suspect someone has blocked you, test out your hypothesis to make sure.
Sign into Twitter. Users block your account, not your IP address or the computer you're using, so you must be logged in to see if you've been blocked.
Type the URL of the profile you think has blocked you into your browser's address bar. If you have been blocked, a "Page Not Found" message appears.
Attempt to send the user a direct message, which a blocking also prohibits. Click the "Messages" button on the Twitter navigation bar that runs across the top of the screen, click the "New Message" button, then enter the username of the person you believe blocked you into the To field. If sending the message fails, you have been blocked.