So you know who these kids are? You call them anonymous, but you also said you have their names.

Honestly, you and your daughter need to sit down with the administrators of her school. If the school has a resource officer, the resource officer needs to have the information also.

This is harassment and needs to be addressed before it goes any further. If administration doesn't respond immediately and effectively, go above their heads. Specifically refer to the terms harassment and bullying (if that applies) because schools are legally bound to intervene.

I am a public school teacher, and this is exactly the kind of behavior that can get so out of hand, but if we aren't told what is going on we often aren't even aware of it because we are working with no information or only partial information. Too often it is only after the fact that we are finally made aware of all of the information.

I would recommend putting it all in writing, including names and dates where you can. Schedule a conference with administration and your daughter needs to be there to speak for herself as much as possible. Administration should be able to tell you exactly what their plan of action will be to handle the situation. They will not be able to discuss specific information about other students with you; there are laws that keep us from doing so. However, they can tell you what they will be doing generally. For instance, they should be able to say they will call in the individuals involved to speak with them and will tell students to cease their actions. They should be able to tell you that they will contact the parents of these students so that those parents are aware that their kids are being put on notice to cease their behaviors within the school environment. There should be a code of conduct in place. Inquire to what the code of conduct procedures and steps are if any further problems occur.

Where possible, schedules can be changed to lessen contact during school hours.

The resource officer (actual police in our district) can tell you how you can proceed outside of the school -- they have different rules/laws that we do inside the school environment. The school has no jurisdiction outside of school property unless it is a school function, so if this harassment is occurring outside of school, law enforcement should be able to tell you what you options are and how they can assist you.