Technically, HughesNet and Viasat do not. Each claims to offer "unlimited data" because neither charges overage fees, but each has a set data limit for its plans. If you hit that data limit before your monthly billing cycle ends, there won't be monetary penalties, but you will experience much slower, throttled speeds for the remainder of that month. So your data may not be capped, but I would call that practice limiting.  Starlink offers truly unlimited data to its standard users. However, that significant advantage over its competitors changed for some customers this April when Starlink introduced its own data cap for priority users. The limit will be a sizable 1 terabyte of data per month (well above the data limits of HughesNet and Viasat), but it's still a significant change from unlimited data.