I am a middle schooler doing a project on social media sites and that is all you need to know about me I personally have no social media or email because in spite of the fact that I like to think of myself as responsible I could still easily be deceived into giving away my personal information to someone i don't know there are bad people out there who might kidnap kids like me and do who knows what to them. Even if age is just a number many people under 13 are much to naive to own a social media account myself included.
I personally think that no person under the age of 16 should be on a social media site, just think of all the predatory types that lurk on the internet like cyber bullies, paedophiles and the like.
Not all kids have the maturity or the ability to understand the gravity of some of these situations and therefore they should not be allowed to use social media sites like Facebook when they're not properly moderated by the site administration team and moderator unlike most online forums which are usually heavily moderated.
Older people are more manipulative and they take advantage of younger people and try to deceive them. And they try to trick them on purpose. On social media sites, older people could make "friends" with kids. And they could trick them into giving out personal information about themselves. And they might even try to get kids to meet with "friends" that they've met online. And once they meet, the adult could kidnap the kid and could hurt him badly. I don't want that to happen.
Age is just a number- you can't exactly base the level of maturity on that. In addition, there are already often age bars on social media sites- for example, technically you can only join Facebook when you are thirteen. But there are quite a few kids MUCH younger than that on Facebook. The thing is, they are vey hard to enforce.
For those reasons, I don't think there should be age bars set on social media sites.