> It means the data is unmetered. Bandwidth may be throttled.
If bandwidth is to be throttled after a specific amount of data has been used (rather than, say, in response to current overall network load), the data is clearly being metered in order to detect when to start throttling.
It's so pervasive that I automatically ignore any mention of "unlimited" regarding bandwidth or total volume of data. These "unlimited" plans are more like "first X amount of data per month at Y speed; Z speed thereafter", but of course that's not catchy enough for marketing...
Infinity times something finite is still infinite. I think this distinction isn't as important as telling people how much data their maximum really is based on how much they could actually use through the system
Contextually from whence we came (10cents a text, pay per megabyte), data being unlimited means no overages.