There is a playable HL2 but its NOT HL2 if you know what i mean. its a game using HL2 engine and some maps :)

Someone 'hacks' Microsoft, and it's cool. Someone 'hacks' Valve and they become the devil incarnate. At the end of the day, Valve weren't secure enough in their procedures. They fucked up. Hell, you'd have thought with the $6m they recently received, they'd put a decent firewall or something in. Also, elements within a graphics card company leak a Doom 3 alpha and they are celebrated. When elements from that same company leak UT2003 they are celebrated again. Yet someone gets hold of software from the beloved Valve, leaks it to the community and there is almost universal condemnation. Me? I don't agree with hacking of any kind... but the fault of this (given the interest in this game) really lies at the feet of the incompetent Valve.

they shouldnt of had the computers connected on the same network which links them to net

Sometimes that's the place where the news happens. What do you want they should do, ignore it?