What can someone do with my IP address?

Less than most people fear. Your IP address shows a rough area and your internet provider. It does not show your name, your house or your files.

What an IP address reveals

• An approximate location: the country, usually the state or city where your provider's equipment sits. On mobile data it is often a different city from the one you are in.
• Your internet provider's name.
• Sometimes, whether the address belongs to a company, a college or a data centre rather than a home.

That is all an outsider can read from the number itself. Look-up sites that promise "exact address from IP" show only the centre of a city or of the whole country, and that pin has sent angry people to the wrong doors more than once.

What it does not reveal

• Your name, phone number or email address.
• Your street address.
• What is on your phone or computer.
• Your passwords or bank details.

Only your internet provider can connect an address and a time to a customer, and it gives that out only on a lawful request, for example from the police or a court.

What a bad actor could really do

Flood your connection. With enough rented computers, someone can send so much junk traffic to an address that the connection slows or drops for a while. This is called a DDoS attack. It mostly happens to online gamers and streamers after an argument. Restarting the router to get a new address usually ends it.

Scan for open doors. Automated tools knock on every address on the internet all day, looking for devices with weak passwords or old software: cameras, recorders, routers with remote management switched on. They do this whether or not anyone "knows" your address. A router with default settings blocks incoming connections.

Get you blocked. If you share an address with someone who misbehaves (common on mobile data and carrier-grade NAT), a website may block the address and you see captchas or "access denied" messages through no fault of yours.

Guess and pretend. A scammer may say "we can see your IP address, your computer is infected" to frighten you. Every website can see your address. It proves nothing. Hang up.

Sensible precautions

1. Change the router's admin password from the one printed on the box, and keep its software updated. See logging in to your router.
2. Leave "remote management" off in the router unless you truly need it.
3. Do not forward ports for a device you do not understand. Cameras and recorders are the usual victims.
4. Keep phones and computers updated. Updates close the holes that scanners look for.
5. In heated online games or chats, avoid direct peer-to-peer voice calls with strangers; they can expose your address to the other person.
6. If you want websites to see a different address, read about VPNs and changing your address.

If you think you are being targeted

• Restart the router, or leave it off for a while, to get a new address.
• If the trouble continues, tell your internet provider. They can change your address and filter attack traffic.
• Threats, blackmail or stalking are crimes whatever the technology. In India, report them on the National Cyber Crime Reporting Portal at cybercrime.gov.in. Keep screenshots.