Monitoring Bitcoins, Ethereum and Zcash wallets

I've been planning to do something with digital currencies for a while and after WannaCry and this week's Petya outbreak developed balance monitoring straight away. There's a couple of reasons why this is useful.

If you have a stash of bitcoins for speculation or as emergency fund to pay ransoms (no you shouldn't, but I'm not judging), you will want to know when something happens to it. Digital currency disappearing without your approval is a strong indicator of either fraud or an evil hacker on your system. You can now configure ShadowTrackr to send a push notification to your iPhone when the balance of a certain Bitcoin, Ethereum or Zcash wallet changes.

You can also use this as a digital booby trap that fires when your VIP is hacked. Just leave (the keys to) a small amount on the VIP's laptop and make sure he knows not to touch it. If you see changes on the blockchain with the address of these canarycoins and it was not your VIP, then for sure the VIP's laptop is compromised. Not every evil hacker steals bitcoins of course, so it doesn't detect every breach. But I think it's still useful because this trick has about zero false positives.

So, why did WannaCry and Petya prompt me to do this now? To be honest, I was just curious how many victims would pay the ransom.