While the distribution problem hasn't been fully solved, there is a partial solution. Seasons one, two, and three are now available on DVD in North America at Amazon. Here's hoping it gets non-hardware-based distribution in the not-so-distant future; the DVD release indicates that the rights have at least been partially cleared for North America.
[Of course, the subtext of piracy pervades all discussion of video content and its accessibility. I personally am not an advocate of the argument that if it's available for free via piracy and that's the only way you can get it that that's a license to just grab it, but that's a debate for another day.]