I just talked with the NOC at Viasat and confirmed that they block a huge amount of Digitalocean IP addresses due to malware. I don't think their normal support agents are even aware they have IP blacklists so requests for unblocks have to be escalated to their security team(which I'm still waiting to hear back from regarding removing the block).
They seem to be blacklisting entire /24 subnets even if only some of the IP's are sending malicious traffic. I've found this to be the cause of many websites not working including some of my own.
The best way I've come up with to test if Viasat is blacklisting an IP from a non-Viasat connection is to try and ping one of the core routers such as 64.125.54.230.
What should one do in situations like these?