Well, its actually the first time I am noticing that feature here, and thanks op for bringing up this thread, forum is indeed packed with lots of features, though most seem hidden, but I hope that as this place gets busier in the coming months and years, all the features will unpack themselves.
@cantsay, before reading the reason for the warning, I was going to say that if that user does make 4 or 5 posts under 5 minutes, I think cautioning and possibly sanctioning him or her is the job of his or her campaign manager, post-bursting I think has nothing to do with the forum as it does not break the rule of the forum, except I am wrong, I will happily accept correction.