what is "secret_society123"?

[Matthew]

i came across a tag on Instagram filled with many pictures involving self harm/suicide and eating disorders.
i'm curious as to what "secret_society123" is, or what it means.

[Emily]

I post things using that tag. I have a secret instagram account. insane__dreams is the username. It doesn't mean anything, its pretty self explainable. Secret society, the numbers are added just so no one finds out. So the instagram company doesn't remove the tag or finds out. We use it for disorders or self harm. Anything of that nature I guess you could say... Please don't self harm. Have a good day.