AT&T did introduce a cap last year.They never could get a reliable method to monitor b/width in all areas.Prior to switching to Charter cable,the online b/width page at AT&T said not to worry about our usage.Charter has a 250Gb cap.Think Comcast in most areas is uncapped until they get the new higher caps set up.They also had a lot of complaints of unreliable b/width usage monitoring.Best I can gather most isps that have caps are in the 200-250gb range according to your plan.We have never come close to the 250Gb cap,we stream on demand,some netflix,amazon,and d/loads.