I don't know if it's a scam per se but if you already pay for cable or satellite, all you really need to do to watch those broadcasts on your computer is the proper TV tuner card.
If you're poor (and bad) like me you might have some luck watching live television for free via this site:
http://www.tvpc.com/ChannelList.phpYou might not be able to watch everything listed there because some stations need plugins and some need a specific browser and some just don't work but for me, I'm able to watch MSNBC when I want and I can get stations like USA Network and Scy Fy and that keeps me fairly contented.
As for Hulu, I freaking love it. I used to have trouble with it using both IE and Firefox but now that I watch it solely with Google Chrome, it rocks. I joined as a free member a good while ago and I think being a member helps with the stream - I could be wrong. My broadband connection is decent but my PC isn't the most powerful in the world so I set my player to 280P and the videos and movies play smoothly.
I haven't done the TV thing since 2006 and I don't miss it a bit.
There's a few other online places where I watch live streams and recorded stuff but for now, TVPC is a good starting point.