Well anonymous jackpot winners are usually the ones who win jackpot prices and decide to keep their identity anonymous to the rest of the world. Even though most of the lotteries winners tend on letting the world know they are newest millionaires in the world, some individuals tend on keeping it private.
But for your information there are some lotteries which allow their jackpot winners to claim their prize anonymously while others require the jackpot winners to go in public according to the country or state in which you purchase your ticket.
For example one of the winners of Megamillions jackpots last year bought tickets at a store in California and as a result she got to collect her jackpot anonymously.the most known cities in which you can keep your identity anonymous are known to be located in the United states.
But most of the lotteries are required to keep at list the basic information about the winners,which should be released to the public ,also the jackpot amount won should be told to the public in order to keep transparency in their operation.