The tweaks allow Steam users to pick and choose what information they share with friends and the wider Steam community, letting them stop people from viewing their 'game details,' which includes the list of titles they've purchased or wishlisted, along with their achievements and total playtime.
Notably, those detailed game stats are now hidden by default (as shown below), with only a user's basic details and profile information being kept public.
That's bad news for outfits like Steam Spy, which relies on purchase information being publicly visible to work out sales estimates of titles launched on the platform.
"Valve just made a change to their privacy settings, making games owned by Steam users hidden by default," tweeted Steam Spy founder Sergey Galyonkin. "Steam Spy relied on this information being visible by default and won't be able to operate anymore."
Valve claims the changes are the direct result of user feedback, and has promised to deliver more privacy tweaks -- such as a new 'invisible' mode in addition to the already existing 'online,' 'away,' and 'offline' presence options -- in the future.