Final answer:
The underlined phrase provides context that describes penalties for violating past cell phone policies. It contrasts past and present policies, shifting from strict bans to productive use in classrooms.
Step-by-step explanation:
If the underlined phrase were deleted, the sentence would primarily lose a detail that describes the penalties for having a cell phone. This phrase provides specifics about the strict consequences of the past policies that enforced a cell phone ban, including fines, confiscation, or suspension. Today, the contrast is evident with some schools encouraging cell phone use for educational purposes, marking a shift in educational leaders' perspectives toward the utility of these devices in learning environments.