American researcers in ohio have proved in 219 students who is using facebook 68% got GPA less than expected.
u know why becuase playing facebook reducing their study. And after that i also have and experience that when i addiceted by poker poker is card game on facebook. Actually i also play poker but now i can control it, u know when was in high school i spent all of my time to play poker, i forgot all things, no study, no sleep, no eat, im afraid if that things gonna happen with another student, expecially elementary student, so how if elementary students open adult materials from the internet, im pretty sure that will crash a morality. So they goverment should limit the use of internet only for educational contents. And i believe the students will be better, than facebooker student, by using internet only for education. And even the government in your country have not limited internet among the student on educational only, if you are student try to limit it by yourself and trust me your score will be great :D