I've been looking in to Litecoin and other Cryptocurrencies later, and given my parallel penchance for VPS', this blog posting on VPS takeover for Litecoin mining was particularly timely:
That wasn't the end of the matter, I was in for a rude shock when I logged into my Amazon account to check for unauthorised usage. $3000+ in pending charges. Woah!
I've had a few VPS' taken over either via weak passwords or in a more frustrating case of a user account having her email breached and scanning for access details. In both cases the attacker has set up SSH brute forcing to compromise other servers - not the end of the world and relatively easy to kill and block once you get alerted.
However, for pay-per-use instances along the lines of EC2, this new trend in spinning up litecoin mining instances is certainly a new one! From various comments it looks like he may not have to pay the full amount, but a good lesson to us all to stay on top of server security; especially on pay per use.
For those interested, Litecoin is the new trend in mining - it can be done most effectively with GPUs - more so that Bitcoin which has been saturated with ASIC devices - but you can still make some headway with good old fashioned CPU mining.