Contributed by BRValentine
"In summary, you can indeed stay overnight in the Bologna
Marconi (BLQ) airport.
I arrived last night around 10:30 p.m. Miraculously there was
someone at the upstairs information desk, who informed me that
the overnight waiting area was restricted to the red chairs
opposite check-in desks 1-22. This rule didn't seem to be
strictly enforced, as a few of the other people waiting through
the night were wandering around a bit without hassle. Thanks to
a tip from the sleepinginairports website I found the reclining
padded wheelchairs and slept in one of them. Very comfortable.
The external doors at the airport claim that they are locked
between 11:30 p.m. and 4:00 a.m. While I didn't check for
myself, I don't believe this to be true as it seemed that more
and more overnighters arrived throughout the night."