Easily. In fact, a T1 is barely adequate for a single person to watch live streaming video. With everything being HD these days, watching Hulu or Netflix over a T1 is painful even if you're the only person using it.
Hulu's requirements say "In addition, you will need a broadband internet connection. We recommend a downstream bandwidth of at least 1.5 Mbps for a smooth playback experience." A T1 is about 1.5 Mbps.
Netflix's requirements say "1.5 Megabits per second - Recommended broadband connection speed. 3.0 Megabits per second - Recommended for DVD quality. 5.0 Megabits per second - Recommended for HD quality". So even a single user couldn't get DVD or HD quality over a T1.
Youtube videos typically only stream at about 1Mbps or less. So a single Youtube video can easily take 2/3 of a T1. If you specifically select a high quality, it can be more.
T1s are not suitable for streaming video.