My father is a professor. He has his rules and while some might find them strict, I like them. Phones... Unless you come and talk to him first with an issue then Day 1 of class they get this statement: "This is your warning! If I see a phone or hear a phone during any class I am teaching you WILL be kick out of the room for the day. This is your warning!!! During exams or lab days if I see a phone or hear a phone, then you fail for that day and are kicked out of the classroom or lab. If you have a problem with these rules you may leave this classroom right now."
Phones... Unless you come and talk to him first with an issue then Day 1 of class they get this statement: "This is your warning! If I see a phone or hear a phone during any class I am teaching you WILL be kick out of the room for the day. This is your warning!!! During exams or lab days if I see a phone or hear a phone, then you fail for that day and are kicked out of the classroom or lab. If you have a problem with these rules you may leave this classroom right now."
This might be strict but they were warned.