Step back from the burgers...
they don't want the fastfood chain, the grocer or the candlestick-maker...
...the fastfood chain is probably just the single biggest list the email service provider handles.
A McFlunky used the cloud-based ESP platform to spam the fresh-meat lists the ESP holds from behind the ESP's white-listed IP. ++deliverability
Other ESP's have also been hit by this (US & UK as far as I know - darkreading has something on it) - and it is looking like it could be a quite an issue.
If i had pwnd an ESP wouldn't be sending unexpected burger email or comedy 419s. you'd spear the ESP clients and customers who might give-up acess to their networks or their users credentials, postal address, bank accounts, usual profit motives etc etc.
It's funny, but not so funny everyone decided not to talk about it... anywhere - in reality it is potentially one of the most troubling breaches in ages - it trickles down through layers (I found out today about 3 ESPs hit by attacks with 1/3 success).