Second Steam account on same PC loaded Save game from other Steam account

JSP869

Why would a Steam account access the saved game for another Steam account just because they're on the same PC?
People share computers, and so a second Steam account should begin a brand new game of MPQ, not give that second person access to the first person's save game.
Customer Service have been contacted via the second account's email address, and hopefully they'll resolve this issue and reset the second account's MPQ save to the game's initial state, and hopefully when that happens it won't screw with the first account's game.