Halevai the mispalelim would wait until the end of davening!
If someone wants to make an appeal and asks the Gabbai for permission, he is told to wait until after davening. By then there is barely a minyan left. The rest of the collectors just walk around freely. That is typical for a busy shul in the middle of Brooklyn.
Note that locking the door is not an option, because just like there is barely a minyan by the end of davening, there is also barely a minyan at the beginning. People continue to walk in late, and very late.
The saddest part is that the first 10 to arrive and the last 10 to leave are mostly the same people!! To paraphrase Shabbos Zemiros – Hameachrin Lavo U’Meharririn Lotzais…