I'd like to know how come it's pretty easy to find demos of HT and HTEP. Were they leaked or released?
linkin park gave copies of the hybrid theory E.P to their fan club members in the first year, they no longer do it anymore
When Linkin Park(then Hybrid Theory) first were getting started they used the internet to gain fans. They went into chat rooms and talked to people and shared their music with people who were interested. That's how it got on the internet in the very beginning.
Some, most likely were kept by the workers at the studio and distributed by them or hacked off their computers.
Technically, a lot of the tracks (not Xero but Hybrid Theory) were distrubuted through the internet. They had a website (hybridtheory.com I think) where they had their E.P. songs up for download. The website doesn't work anymore, but I've seen it before, and it's had a 'download mp3s' link and did have a few of the E.P. songs on the page available to download (at the time). As Bryan said, they went into chatrooms, where ever where people liked their type of music and just promoted away. As for Xero stuff, someone probably just got their hands on the tape, and recorded the stuff to a CD or something, then distrubuted it.