macuahuitlgog: I have a question relating to privacy. Steam, GOG and Gamersgate have our real names, addresses etc. Are they allowed to give out this kind of information like candy to strangers?
You should be more worried about the Einwohnermeldeamt, Standesamt, etc.
They are well known for selling your private data to organisations like the GEZ.
But to answer your question:
GOG does not store that data at all.
Steam does store the data (obvious if you must verify your account ownership) and:
Personally identifiable information will be processed and stored by Valve in databases situated in the United States. Valve may allow third parties performing services under contract with Valve to access stored information but such access shall only be to the extent necessary to provide those services. In those instances, the third party will be bound by the terms of this privacy policy.
Valve may release personally identifiable information to comply with court orders or laws that require us to disclose such information
http://www.valvesoftware.com/privacy.html The Gamersgate website does currently not load for me, but here is the privacy policy:
http://www.gamersgate.com/info/privacy-policy EDIT: Now Gamersgate loads for me:
From what I understand, you can voluntarily give them information (what about when buying? I see nothing on that) and they more or less feel free to share it with third parties like Valve does, but also in addition to partners and affiliates. Happy spam!