A question about airport security

When I arrived at Paris CDG airport earlier today, they had closed access to the gates while the terminal still remained open. They also closed the exit for those passengers who just arrived. They were looking for somebody who had placed a suitcase somewhere and I believe this was the reason for closing the doors. I can't tell for sure because there was absolutely zero personnel around, neither security nor service. When they opened up the doors again, at least six or seven ladies showed up to scan the boarding passes.

So there where a couple of hundred people waiting to proceed... from both sides. With what happened at Istanbul airport this week, I didn't feel very safe where I was. In fact,I felt VERY UNSAFE. Isn't that a perfect target for any terrorist? Please share your thoughts with me, have you made similar experience?