The Realm of Exchange, also known as the Realm of Questions and Answers, is divised in many little states. Some of these famous states, and the ones which will interest us today, are Overflow, Arqade, Travel and Worldbuilding. Every people living there, known as the "Users", are free to travel through these lands and to ask or answer questions, as long as they follow the rules of these states. So every citizen of the Realm of Exchange can get the citizenship of different of these states.
The realm was living beautiful years of peace, until one day when the 4 states mentioned above started a bloody war, because one of their citizen had been killed, and each state started to blame the others for this crime.
You are a citizen of the Realm of Exchange and of the state of Puzzling. You made it your mission to solve this mystery and to bring back peace on the realm of Exchange. The first step for you is to try to figure who has been killed. One of the other inhabitant of Puzzling seems to know who that person is, but refuses to give you the information directly. You totally understand, as a good citizen of Puzzling wouldn't share a good information without hiding it in a puzzle before.
The man gave you a piece of paper where was written the following message:
With just this information, will you be able to find out who has been killed?
(Disclaimers: This set of questions is obviously made in the purpose of fun and puzzles. If anyone used as a character in these questions feel offended by this puzzle, do not hesitate to tell me so.)