What Does it Mean to Flag Something on Facebook?by James Wright
Flagging or Reporting
"Flagging" is the term many people use in place of "reporting," meaning that you're alerting Facebook staff about content that is inappropriate and that needs immediate attention. The term is used ubiquitously, so you can flag a post for spam as well as flag a personal message for abusive content.
Facebook's staff can't keep track of everything posted to the site, so it relies for help. Flagging enables you to notify staff of inappropriate advertisements, flag fake accounts, and report signs of harassment, abuse or threats. The staff takes reports seriously, and its abuse team analyzes each individual report.
How to Report
Every feature on Facebook has a reporting function, but each is accessed differently. For example, on any post in your feed, click the grey arrow that appears when you hover your cursor over the individual post and then click "Report Story or Spam." To report personal messages, open the conversation thread containing the offending post, click "Actions" and then click "Report Spam or Abuse." The complete list of all report functions can be found in Facebook's Help Center (see Resources).
If you are being harassed or threatened, or if you observe its occurrence, report it immediately. Abuse is not tolerated on Facebook and will result in a permanent ban. No matter what or who you are reporting, all reports are anonymous. However, Facebook also does not discuss the results of reports with other users, and filing a report does not guarantee that action will be taken -- only that staff will review the flagged material.