As of this time, this thread is viewed ~8129 times. Given this number, I am not surprised that the collected address reach 4200+. I believe 80%-90% of them are legitimate. Since Bitcointalk is an open forum, people can view this thread and join the Airdrop without registering or commenting on this thread.
very happy for joined this project, can not wait to get my 32000 coins , hope the airdrop will start soon. good job dev