File sharing is useful when you want to open a document from a laptop on your desktop, move photos between devices, or access a shared family folder at home. But when file sharing stays enabled everywhere, your device may expose more than you intended, especially on public Wi-Fi, shared apartment networks, hotels, airports, schools, coworking spaces, and guest networks.
The safe rule is simple: turn on file sharing only when you need it, only on trusted private networks, and only for specific folders.
What is file sharing on a computer?
File sharing lets one device access files stored on another device over the same network. For example, a desktop computer might share a folder so a laptop can open or copy files from it.
That sounds harmless, but the risk depends on what you share, who is on the network, and how the sharing permissions are configured. The FTC’s peer-to-peer file sharing guidance warns that when file sharing software is not configured properly, files not intended for sharing may become accessible to other users.
Why should you turn off file sharing on public networks?
Public and shared networks are unpredictable. You usually do not know who else is connected, whether the network is secure, or whether someone is scanning for exposed devices.
CISA’s wireless network security guidance explains that unsecured wireless networks can allow unintended users to monitor traffic, steal personal files, or access exposed systems. That is why file sharing should stay off when using coffee shop Wi-Fi, hotel Wi-Fi, airport Wi-Fi, campus networks, library Wi-Fi, or any network you do not control.
How does turning off file sharing help someone become safer online?
Turning off file sharing helps someone become safer online by reducing the number of ways strangers, malware, or unauthorized users can reach private files. Cybersecurity professionals call this reducing your attack surface.
This habit helps protect:
- Tax documents
- Resumes and job search files
- Family photos
- Medical records
- Financial statements
- Work documents
- Password files or exports
- Backup folders
- Personal identification scans
The FTC’s data security guidance emphasizes collecting only what is needed, keeping sensitive information safe, and disposing of it securely. The same principle applies to consumers: share only what you need, when you need it, with only the people or devices that need access.
What can go wrong if file sharing stays on?
Leaving file sharing enabled can create several avoidable risks:
- Someone on the same network may browse shared folders
- A misconfigured setting may expose an entire drive
- Malware may spread through shared folders
- Private documents may be copied without notice
- Work files may become visible on personal networks
- Old shared folders may remain open for years
- Guest devices may access files they do not need
The FTC’s file sharing guide notes that users can accidentally share drives or folders containing sensitive information, and once files are downloaded by someone else, the original user cannot reliably retrieve or delete those copies.
How big is the risk?
Misconfigured sharing has caused real exposure. In a Federal Trade Commission probe reported by Dark Reading, the FTC notified almost 100 organizations that personal information from their networks was available on peer-to-peer file-sharing networks, including sensitive customer or employee data. The FTC’s findings, covered in Dark Reading’s report on P2P data breaches, show how easily file sharing mistakes can expose private information.
Even though that example involved organizations, the lesson applies at home: one wrong sharing setting can expose far more than intended.
Should you create a separate folder for file sharing?
Yes. Instead of sharing your whole Documents folder, Desktop, Downloads folder, or entire drive, create one folder just for sharing.
Use a folder name like:
- Shared home files
- Family transfer folder
- Temporary file share
- Printer scan folder
- Photos to copy
Then move only the files you actually want to share into that folder.
Safer file sharing setup
Use these settings whenever possible:
- Share one dedicated folder, not your whole drive
- Require a password for access
- Turn off guest access
- Give read-only access unless editing is needed
- Remove old shared files after transfer
- Disable sharing when finished
- Avoid sharing folders with tax, banking, medical, or work data
- Use cloud sharing links with expiration dates when appropriate
How to turn off file sharing when you do not need it
You do not need to be technical. Just make file sharing a quick privacy check.
On Windows
- Open Settings
- Go to Network & internet
- Open Advanced network settings
- Select Advanced sharing settings
- Turn off File and printer sharing for public networks
- Review private network settings and turn sharing off if not needed
On macOS
- Open System Settings
- Go to General
- Select Sharing
- Turn off File Sharing
- Review any shared folders and remove what you do not need
On shared Wi-Fi
Before joining a public or guest network:
- Turn off file sharing
- Turn on your firewall
- Avoid opening shared folders
- Do not transfer sensitive files
- Use a VPN if needed
- Mark unknown networks as public, not private
File sharing should be temporary, limited, and intentional. Turn it off when you do not need it, avoid using it on public networks, and create one dedicated sharing folder instead of exposing your entire drive.
