Delete a character, NO! But taking their name, assuming they are not being used for in the future and to be used out of spite so nobody can use it, YES!

An example would be the player that created Roy Mustang on alot of servers, he/she probably did this so others can not use it. A friend of mine hates the Naruto characters so whenever a new MMORPG launches, first thing he does is create alts with the main character names and create them on as many servers as possible. He benches them and never touches it again.