It doesn't have one.... If you are looking to report a problem, or report abuse, in the tope right there should be a little link that says "report abuse"... Click there and follow the steps.
If there is child abuse, report it to child protection services.
50% of people would report the abuse
go to the bottom of the page and press report abuse
Anyone.
yes facebook does have a report abuse button if you don't believe me check for your self
Twitter has a form that you can fill in to report abuse. Follow the related link to the form.
Report abuse to any person that you trust completely.
You can report them by clicking "report abuse" just above the question. Then describe the abuse in the report you file.
The "report abuse" link is available to all contributors.
the one who see child abuse
50% of people would report the abuse