Is live streaming from TV stations legal?

Hello friends,
I would like to know if "Live Streaming" is legal or illegal? I've seen many websites support live streaming of sports and other channels, such as pay-per-view channels / movies, and some software programs, such as TVU and SopCast, that help you stream any desired channel.

Is it bad?

If so, who is the culprit?
1. The software providers (SOPCAST, TVU, etc.) that allow broadcasters to broadcast.
2. The channels that use the software to broadcast the TV channels …

Is live streaming from TV stations legal?