13TB of Steam data spanning a decade has leaked online, including beta builds of Portal 2 and Left 4 Dead 2

Valve

More than 13 terabytes of Steam depot data, covering the period from 2003 to 2013, has been made publicly available via torrent. Dubbed the "Steam2" leak, the dump reportedly contains pre-release builds for thousands of games including Portal 2, Left 4 Dead 2, Dragon Age: Origins, and Batman: Arkham Asylum, and is being described by some as potentially the biggest leak in Steam's history.

The details:

The leak was first publicised by Gabe Follower on X, who says the data was obtained from a "publicly accessible endpoint" on Steam's servers that still required authorisation to access. The contents are being actively catalogued on GitHub as the community works through the size of the dump.
The 2003 to 2013 window is significant: Steam launched in September 2003, and Valve reportedly switched to a new storage system around the time SteamOS 1.0 released in December 2013, which appears to explain both the start and end dates of the leaked data.
Ex-Valve developer Elan Ruskin, who worked on Half-Life 2: Episode Two, Portal, and Left 4 Dead 2, addressed the leak directly on X. "Every good idea we had went into the final thing we shipped," he wrote, "and anything not in the final version was not a good idea."
Given the scale of the dump and the early stage of analysis, unverified claims are already circulating online. Valve has not commented publicly.

Working in games? Find your next role with a Free Hitmarker Profile.