Bioware's technical producer Derek French recently revealed that Mass Affect will feature a copy protection system similar to that used for BioShock, but that it will require online authentication once every ten days.
"After the first activation, SecuROM requires that the PC re-check with the server within ten days (in case the CD Key has become public/warez'd and gets banned)," said French in a BioWare forum post.
If the game cannot be authenticated over the internet within ten days then the game will stop working.
"After 10 days a re-check is required before the game can run...An internet connection is not required to install, just to activate the first time, and every 10 days after," said French.