People being hacked since the last Server Check.

The rate is limited by several factors;
The # of people who are aware of the exploit (and more importantly the # of people who actually know how to do the exploit), the difficulty/time constraints/requirements to use the exploit, and the number of simultaneous exploits each person who knows how to do it can perform.

It's impossible to get a true idea of the potential rate of the breaching without knowing those factors and it's equally impossible for us to gauge how fast they're moving based on existing breaches because we don't know how many people have been hit, how many of them were via the same vector, or exactly when they occurred.

Only whomever is actually doing it can tell us the limits.

Also, they may be slowing down just to keep the number of hackings within "reasonable error margins" so nothing is done about it.

Based on what the guy who changes his pass every 2 weeks said earlier, I somehow doubt it was a one-time dB exploit at this point, sadly.