Short answer is the school is probably singing their own certificate instead of going with a CA(certificate Authority ), the reason chrome us complaining about it is because it can't verify it's authenticity.
The reason you are seeing it is because they are probably routing all traffic through a proxy or a UTM, by installing the schools certificate it allows them to decrypt all you https (ssl) traffic. Personally I wouldn't install it, I don't like people spying on me.
[–] [deleted] 0 points 1 point 1 point (+1|-0) ago (edited ago)
[–] Sweet_BBJesus [S] ago
I said 'appears to be' for a reason. i'm not saying they're trying to do so, otherwise i would have posted this over at /v/conspiracy i legitimately wanted to know why this message was appearing everytime i would try to connect no matter what from.
[–] [deleted] 0 points 2 points 2 points (+2|-0) ago
[–] Sweet_BBJesus [S] ago
Cheers for the reply!