If a school or library receives e-rate funding then they are required by law to monitor students online activity and protect their privacy from 3rd parties. They also typically have security practices that must be in place for their insurance company. The school board and parents could whine and complain about student privacy all they want but the law and their pocketbooks will make these decisions for them
And it’s not like the traditional banking industry is energy efficient. I would argue that they use more power especially if you consider the lifestyle of banking executives.