Some people download tremendous amounts of stuff they don't need. This lifestyle is incompatible with A&A quotas (at your big name ISP it's actually costing them more than you pay for the service, but they have so many customers they don't care unless it gets entirely out of hand).
Hear a passing mention that "Bob's Cheese Factory" is good on the podcast you listen to in the shower. Find out there were six seasons, OK, download six seasons of the Bob's Cheese Factory show, equating to 60 hours of video. That evening, watch the first twenty minutes of the pilot, seems kinda flat, delete all sixty hours.
Similar behaviours exist in many aspects of life, there are people who own hundreds of items of clothing they'll never wear, for video games we know an on-line only title will see a staggering number of purchasers who never even go on-line with it once, meaning they paid for it, but they have never played even a few minutes of it, many of us order far more than one reasonable meal per person for take out food.