Kaj was a user on the programming website, Scratch. He/she made claims about destroying the website, due to wanting to get more views. Although Kaj is no longer on the website, s/he is often blamed for so-called "hacking" into other users' accounts. This user has arguably gone down in Scratch legend.
Kaj was a regular user on the Scratch Website; s/he joined in 2008. S/he originally had no intention of causing harm. However, Kaj developed a desire for more views on the projects s/he had created. After a while, Kaj got extremely annoyed about not getting more views and created a project threatening to destroy Scratch. After a lot of inappropriate behavior, Kaj was banned from the Scratch Website. The Scratch Team gave Kaj the opportunity to have his/her ban revoked, but s/he never replied. When someone who claimed to be Kaj contacted the Scratch Team (with decent evidence), they used the male pronoun, rather than the female used in old comments.
Misconceptions and Conspiracies
Many users (especially older Scratchers) put the word "Kaj" in their username to scare other Scratchers. These users often leave comments threatening to hack other Scratchers and destroy Scratch. Despite what most people believe, the real Kaj never stole or hacked any accounts. Occasionally, well-known users have their passwords guessed, and somebody pretending to be Kaj claims it was them.