We hope these problems are only temporarily and will disappear soon.
I too hope that we will not see a repeat of this PM spamming, the first I've heard of in the time I have been on the forums.
Perhaps a suggestion, to restrict the number of members you can PM at once to say 5 or 10. I appreciate that this may impact on some members legitimate use of the PM facility, it would make it less attractive to drive by PM spammers.