Requiring Ten Listeners: Tos. Berachot 8a #1
Leaving during Reading of the Torah: Berachot 8a
Learning during Reading of the Torah: Berachot 8a, Rosh Berachot 1:7
Talking during Reading of the Torah: Tos. Berachot 8a #1
[Regrettably,] there are many who leave and enter while the Torah is being read: Megillah 22a
