We recently reported that the PC version of Mass Affect was going to include anti-piracy software that would reauthenticate the game every 10 days.
After hearing the outrage from the community, they have recently announced that they will be dropping the 10-day reauthentication, and will only require online authentication when the game is installed. Mass Affect will also require authentication when there is new content installed.
The game will also be limited to three authentications, but BioWare has assured users that customer support will be available if additional authentications are needed.