https://www.pcgamer.com/steams-new-privacy-update-will-apparently-ruin-steam-spy/

Valve has updated Steam's Profile Privacy Settings page, with a new range of control options for how users' information is displayed in the Steam client. Now you can choose who can see which games you've purchased or wishlisted, as well as other information like achievements and playtime. In Valve's words "you no longer need to nervously laugh it off as a bug when your friends notice the 4,000+ hours you've put into Ricochet".

But according to Steam Spy operator Sergey Galyonkin, one new change to Steam's privacy settings has rendered the popular stats tracking site useless. "Valve just made a change to their privacy settings, making games owned by Steam users hidden by default," the Steam Spy Twitter account tweeted. "Steam Spy relied on this information being visible by default and won't be able to operate anymore."