You fought 5 enemies at once and none of them survived

You brought about the Lord Regent's fall from grace by broadcasting his crimes

You reached the top of Kaldwin's Bridge

Complete the game on Normal

Unlock a hacked version of one of the Abstergo videos in the story quest.

GTA Online: Finish a Gang Attack without dying and kill at least 10 enemies.

Complete Act 1

Become leader of The Lost. (The Lost and Damned)

Tag 100 enemies

Upgraded a weapon at a Power to the People Station.

Take down Maurice

Complete Studio 101