For instance, I can post anonymously right now on this very platform. How is that wrong?
At the first level, slashdot will log all the IP addresses of all submissions - that's part of the general infrastructure of discussion forums. At a second level someone can contact the maintainers if anything offensive has been written. Then at the third level, they can hire a lawyer and request the IP address of the person submitting the comment. From there they can escalate the complaint with the originating ISP, the authorities and the individual concerned.