Suing an anonymous online poster
Unmasking is a separate legal fight before the actual case begins, and courts protect anonymity by design.
You generally file a claim against an unnamed defendant, then seek a court-ordered subpoena to the platform or internet provider for identifying information. Courts apply protective standards first, usually requiring you to show your claim has real merit before anonymity is stripped. It is slower and more expensive than most people expect, and often yields only an IP address.
The two-stage structure
Stage one is unmasking. You file against a John Doe defendant and apply for permission to subpoena the platform. Courts do not grant this automatically, because anonymous speech has constitutional protection.
Most courts apply a test requiring you to make genuine efforts to notify the poster, identify the exact statements at issue, and show your claim could survive a dismissal motion. Only then does stage two, the actual defamation case, begin.
You have to prove your case is serious before you are allowed to find out who to sue.
What you often get
Platforms typically hold an email address and an IP address. That may lead to an internet provider, another subpoena, and an account holder who is not necessarily the poster.
VPNs, shared connections and burner accounts frequently end the chain entirely. It is common to spend meaningful money and arrive at nothing usable.
Before you start, weigh the exposure
Unmasking litigation is public. The filing itself can be reported, and the statements you object to are quoted in documents that then rank in search results.
Some states also have anti-SLAPP statutes allowing a defendant to have a weak claim dismissed early with your costs awarded against you. That risk is real where the content is arguably opinion, and it is the reason a candid assessment of the fact-opinion line, covered in defamation vs opinion, belongs before the decision rather than after.
Common questions
Will the platform just tell me who it is?
No. Platforms generally require legal process and many notify the user first, giving them an opportunity to object.
How long does unmasking take?
Months is typical, and longer where the poster contests it or the chain runs through multiple providers.
Is it worth it?
Sometimes, where the harm is severe and ongoing. For a single bad review it almost never is, and platform routes should be exhausted first.
Find out if it can come down.
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Working through this for a business? See Reputation management for attorneys.