The question of whether they are children or adults, IMHO is moot. If it's true that they're blocking gay sites while allowing anti-gay sites, then we are dealing with discrimination, not the appropriateness of content.
The post above discusses whether we can trust the government to do the right thing and make it illegal to block these sites. IMO, if you wait for the government to handle this, you've already lost the battle.
The people that feel outrage at this are the ones that have to do something. A simple proxy shared with the students, gatherings, protests and boycotts would make changes on the local level initially and gaining in size, a global level.
The legal system however, would not.