A long time ago, I bought Half-Life 1 in a regular store. I tried to play with a friend online but it said my CD-key was already being used. Turned out my frien

A long time ago, I bought Half-Life 1 in a regular store. I tried to play with a friend online but it said my CD-key was already being used. Turned out my friend had bought the game, came without a CD-key printed on the box, so the store opened a random box and gave him that CD-key. I bought that exact same box. In the end, my friend sent a picture of the box to Valve and got a fresh CD-key, and we could finally play together.