What is the ruling on confiscating food brought by students from outside government schools, which the administration prohibits from being brought in, and then giving it to the guard or worker?

If preventing students from bringing food aims to boost the school's sales, then this is an impermissible injustice, and confiscated food constitutes unlawful appropriation of wealth. However, if the prohibition is for a legitimate interest, then confiscating food depends on the permissibility of financial chastisement (ta'zeer bi al-mal), which is a point of contention among scholars, with most of them disallowing it. Indeed, a consensus has even been نقل (reported) on its impermissibility. Confiscation can be replaced with other punitive measures such as reprimand and deprivation from activities.