Technically, no. But it is generally in good taste of the teacher to respect the student's privacy and simply turn the phone off.
In January 1989 the Internet Architecture Board (IAB) issued a statement of policy concerning Internet ethics. This document is referred to as RFC 1087 'Ethics and the Internet'.
An extract of RFC 1087 follows: Teaching
Internet privacy involves the right or mandate of personal privacy concerning the storing, repurposing, provision to third-parties, and displaying of information pertaining to oneself via the Internet. Privacy can entail either Personally Identifying Information (PII) or non-PII information such as a site visitor's behavior on a website. PII refers to any information that can be used to identify an individual. For example, age and physical address alone could identify who an individual is without explicitly disclosing their name, as these two factors are unique enough to typically identify a specific person.
Internet privacy forms a subset of computer privacy. A number of experts]weasel words[ within the field of Internet security and privacy believe that privacy doesn't exist; "Privacy is dead – get over it" according to Steve Rambam, private investigator specializing in Internet privacy cases. In fact, it has been suggested that the "appeal of online services is to broadcast personal information on purpose." On the other hand, in his essay The Value of Privacy, security expert Bruce Schneier says, "Privacy protects us from abuses by those in power, even if we're doing nothing wrong at the time of surveillance." Privacy concerns have been articulated from the beginnings of large scale computer sharing. Teacher
Hospitality is the relationship between the guest and the host, or the act or practice of being hospitable. This includes the reception and entertainment of guests, visitors, or strangers.
The word hospitality derives from the Latin hospes, meaning "host", "guest", or "stranger". Hospes is formed from hostis, which means "stranger" or "enemy" (the latter being where terms like "hostile" derive).