It depends on the tool that you use. Some programs will automatically block any websites that include links to Facebook and unfortunately that means that half the Internet will no longer work. However, I use a cool ad-blocker for Chrome called uBlock Origin. After installing it, right-click its icon, then choose Options. In the tab that opens up go to My filters, then simply type www.facebook.com and click on Apply changes. This will prevent the browser from loading Facebook content without denying access to other websites.