If you're concerned that your Facebook account may have been hacked, you can check to see what activity has occurred on your account. Here's how:

1. Log in to your Facebook account.

2. Click the arrow in the top-right corner of the screen and select "Settings."

3. Click on the "Security" tab.

4. Scroll down to the "Where You're Logged In" section and click on "See More."

5. You will see a list of all the devices that are currently logged into your Facebook account.

6. If you see any devices that you don't recognize, click on the "Log Out" button next to the device.

You should also change your Facebook password immediately if you believe that your account has been hacked. To do this, click on the "Change Password" link in the "Security" tab.

Here are some additional tips for keeping your Facebook account secure:

* Use a strong password. Your password should be at least 12 characters long and include a mix of upper and lower case letters, numbers, and symbols.

* Don't share your password with anyone. This is the most important thing you can do to keep your account secure.

* Be careful about clicking on links in emails and text messages. Phishing scams often use links that can compromise your account if you click on them.

* Regularly review your account activity. This will help you to spot any suspicious activity that may indicate that your account has been hacked.

If you believe that your Facebook account has been hacked, you should report it to Facebook immediately. You can do this by clicking on the "Report a Problem" link at the bottom of any Facebook page.