https://api.steampowered.com/IDOTA2M...chDetails/V001

So the account ID is replaced with a bogus number if their settings is set to not "expose public match data".

This means all the top players on stratz.com I can no longer go see their games and replays, even though technically every replay is available if you bother to download every match.

Bit of an extreme interpretation of european privacy laws.