We're still seeing issues, and despite my streamlining of my contact code, we're still getting bombarded. We've experienced a LOT of memory usage overages in the past month or two, due almost entirely to the spamming. This was the direct cause of our outage on Sunday.
I have set up a logfile to allow me to track who exactly is hitting us so hard. In the short term, I can block their IP from accessing my server. In the long term, I'll do all I can to report them as spammers (not that it'll do a lot of good). Hopefully, I can stay one step ahead of them and help our performance.