actually they do. And in some markets they don't throttle or cap. When I had them in CLE (images are posted on here) I could easily download over 50gigs per month and nothing. At one point I hit over 10 gigs in one night with 4 DTV boxes updating on the connection plus PPV. Not to mention 3 students where using it and the one worked for a major Hospital in Cleveland and was always working from home uploading major documents to their VPN.
