This is a very clever use of twitter. A game has been set up, using twitter as a playing mechanism, to publicise the release of Terminator Salvation (Terminator 4).
Info here: but in essence you follow the twitter account @resistance2018 then get sent messages with challenges that you have to complete. You get points to complete challenges, and the people with the most points at the end will get prizes.
"Resistance Assignments (Abbreviation: RA) will be of the following types:
- Word Mix (Abbreviation: WM) - Word Mix is a simple jumble of letters that need to be unscrambled. Ex: "OHJN" is "JOHN"
- Trivia (Abbreviation: TR) - Trivia questions require simple answers about Terminator Salvation. You may often be directed to the website to find the answer.
- Partial Transmission (Abbreviation: PT) - Partial transmission is a simple letter, word or combination of both that you must fill in and then reply with the complete message. Ex: "_O_N" is "JOHN"
- Skynet Warnings (Abbreviation: SW) are informational messages related to the war between humans and machines.
- Terminator Salvation Updates (Abbreviation: TSU) are information about the film. The updates may also reinforce the instructions and provide tips on how to earn more points.
- Status (Abbreviation: STAT) are direct messages that update you on your points and rank in the game."
See also the official site here, featuring a multiplayer game.