How do I find out who's at a particular IP address?

As you can see, this is a question I get a lot. It’s a very serious
issue for some people.

Unfortunately, though I’ve answered this question a few times in a few ways,
I keep getting various versions of the same question almost daily: “Can I find
out who’s at a particular IP address?”

No, you cannot.

Here’s why and what it really takes …

I’m going to say this a few times because people don’t seem to get it when
I’ve said it in the past, so please bear with me:

No,
you cannot get someone’s name, phone number or specific location from
their IP address.

I’m not trying to be a smart-ass or intentionally mean but please, read that
sentence again. I’m trying to be as clear as I can be so that people will get
the answer.

Now, you can’t do it, but the police (or law-enforcement in
general) can. But for some reason people think that because the police can,
anyone can. That’s just not the way it works.

Here’s what I believe it takes to track someone down by their IP
address:

1. Contact law enforcement. If no laws have been broken or if
   the police don’t have the resources or interest to help you, then you can stop
   right here. I don’t know of anything else you can do.

2. The police use public information to locate the ISP who owns the IP
   address. You can do this yourself using the whois tool at arin.net. For example, you can
   look up Ask Leo!’s IP address and you’ll see that the owner of the IP is
   Rackspace, my hosting service.

3. The police then get a court order. I’m no lawyer, but the
   way I understand it is that this implies the police have enough evidence to
   believe that a crime has been committed and can convince a judge of that.

4. The police present the court order to the ISP who can then
   search their records for information relating to the specific IP address.

5. The ISP identifies the user of the IP address. Note that
   even if you get this far, depending on the type of IP address, the information
   provided to the ISP by the customer, and the length of time that’s passed, the
   IP may not be able to provide any helpful information anyway. I’d expect that
   typically they can, but there’s no guarantee.

It’s actually even worse in some cases. If the IP resolves to a company or
other organization, then it could be any employee at that company. If the IP is
shared, perhaps by a NAT router, then there’s often no way to tell which
computer sharing the IP was being used. If the IP is dynamic, then the IP
address could indicate one computer one day, but another on another day.

Oh, and if the IP address resolves to an ISP in a different country, then
things get even more complicated, as other countries may not care or
may not have the resources or expertise to help.

So, no, you cannot get someone’s name,
phone number or specific location from their IP address.

It takes the help of the law enforcement, the courts or whatever legal
system applies in your country to get the information from the ISP that owns
the IP. And even then you could be out of luck.

•

Please understand that I’m not trying to be unhelpful. I really do
sympathize with the many, many people who are facing issues such as abuse or
theft across the internet. My concern, and the reason I’m trying to be extra
blunt and clear in this article, almost obnoxiously so, is that there is no
silver bullet, no secret answer, no magic answer, and you should know that.
Having an IP address gets you nothing unless you have a situation that can
involve the legal system.

Again:

There is no magic answer. You cannot get
someone’s name, phone number or specific location from their IP address.

Only law enforcement with the help of the ISP can.

If you find yourself in a situation where you need the information, contact
the police, contact a lawyer, or contact some other appropriate legal resource
for advice and assistance.

•

One Possible Alternative

As I pointed out above, you can determine the ISP who owns the IP
address using the ARIN Whois
tool.

One approach, if you are experiencing issues with someone coming from an IP
address owned by that ISP is to complain to the ISP. They may not respond
or act, so you may be no better off than you were before. But they
may.

What they will not do is tell you who owns the IP
address. In fact, if you actually ask for that information I’d be shocked if
you got a response. But if you clearly and rationally state your case the ISP
may take action against the owner of the IP. Or not.

They just won’t tell you who it is.

•

(Unfortunately history shows that the majority of comments to the article
will be “how do I find someone’s name/address/phone number form their IP
address”, even though that’s what the article has attempted to be brutally
direct about. As a result, I won’t be taking comments on this article. I
apologize to all who might have had legitimate comments and additional
information.)