Teachers are responsible for what children do in school. Parents are responsible for what children do outside of school. What happens on social media sites and apps should have nothing to do with schools and if there is a problem with social media then the childrens parents can handle whatever happened.
Students know that what they put out there is public and can be viewed by anybody. It is their responsibility to acknowledge the things they say and do and act upon those. Outside of school students are no longer students, they're people and children and should have the ability to do what they enjoy without having to worry about being watched or monitored all the time.
It's the parents who have to deal with their child. Schools can't act like the parent of the students. What are the parents supposed to do? If there is an issue at home the parents need to deal with it. Also people need privacy. Who cares what they do (unless it's bullying) and this is the last time I'm gonna say this, the parents need to handle it
If students misbehave outside of school, then it is the parents responsibility to deal with this. If a student threatens another student outside of school, via social media, then the parent of the victim should contact the police. It is not a matter to be taken into the hands of teachers. A lot of the time, even though cyber bullying does exist and it is extremely serious, it can be some petty argument over Facebook over a menial thing, that could have been resolved otherwise, without the intervention of school. Anything a student does inside of school is the school's business. Anything the student does outside of schools should not even be a thought process for teachers - it has nothing to do with them.
During school it is the teacher and principals job to monitor and punish students if needed, but after school if done it becomes the parent's job even during school it is there job. The school should be aloud to monitor them but they should not punish them. The school needs to notify the parents and if the parents don't do anything about it and the misbehavior continues then the school should be aloud to do something. Bottom line its the parents job to punish and monitor but the school needs to monitor too.