This "problem" is even more on Mailing Lists (cause of greylisting), if someone tests some conditions and is not as fast as the other ones it often is that 5 messages with nearly same content arrive at the same time. if I am the last of the "helpers" it perhaps comes to my mind that i might "look silly" solely to the fact that i needed the longest to test and write it down ... People generally dont want to look silly ;-)