The site has become a place where memes are born, but also where pornography is rampant. Why? Unlike other sites with open message boards, users are completely anonymous. You cannot even register for a username. If you do want to "identify" yourself — that is, make sure others know it is the same person posting something on one part of the site as another — you can create a "tripcode" or "secure tripod" which is randomly generated by the site's server. Only that server has the IP address that can trace a post back to the user it came from. Users, who can only start a new thread by posting an image (further emphasising the site's focus on photos and drawings), are completely masked to the outside world, making it harder to apprehend them even after posts are taken down by 4chan's administrator.