Mysterious spike in comment spam spotted

Last week, our servers at Mollom have been actively tracking a spike in spam traffic across the 30,000 sites that we actively protect. And when I say "spike", I should say "three-fold increase". Fortunately, Mollom blocked all the pesky comment spam. As promptly as it came, the spike suddenly went away. Something is going on out there ...

Text analysis october
The Y-axis shows the number of requests per second. The X-axis shows the day of the month. The graph is for one Mollom server only.