If it looks too good to be true, it probably is.
It was.
Automattic.com “locked-on” to one of my JetPack-using sites, firing thousands of requests, and resulting in my hosting account getting suspended. I’ve had to remove it from ALL sites, just in case.
Not Impressed! 🙁
P.S. This happened some time ago, I’ve just realised that I hadn’t mentioned it, and I don’t want to give the impression that JetPack is working fine – it’s NOT!