Today, "unlimited" just means you won't be charged for going over a
certain data threshold. Instead you'll be either slowed and/or prioritized. Simply stated, it does not mean you're guaranteed full-speed,
Viasat's unlimited data plans also include throttling of detected video streams with no video stream quality gurantees.
All ISPs publish their disclaimers and fine print whether you miss them or not in the rush to sign up for something that sounds too good to be true (usually it is). Here are Viasat's: