I can't remember where I said it, but somewhere yesterday I suggested it seemed like that Russian Mafia hacking/extortion scam from a few years ago.
They caused havoc with a lot of sites I used and that was the last time outages were a serious concern to me.

One thing will change for me from here on in where Betfair is concerned. The refresh rate on my market position spread sheet will be much faster. If they are going to go down like that again at least I'll know where I'm at.