I have read many posts about TSA agents not having the authority to detain passengers and how passengers are not required to follow TSA instructions to freeze during "Bravo" drills.

Based upon this, what authority does the TSA have to trap passengers in the secure area of the airport?

From a post in another thread, it appears that passengers were trapped in sections of the secure area at DTW.

http://www.wxyz.com/news/detroit-met...rt-on-lockdown

It seems like passengers were trapped here, against their will (from the photos, it appears that the passengers were detained).

Also, are barricades restricting passengers to parts of secured areas in airports common? I have read about many "Bravo" drills but never anything like what happened at DTW.