In March 2018, a Facebook status update meme began circulating across social networks:
Mark Zuckerberg, CEO of Facebook, invented the word BFF. To make sure your account is safe on Facebook, type BFF in a comment. If it appears green, your account is protected. If it does not appear in green, change your password immediately because it will be hacked.
The origin of the claim remains unclear, but like many other rumors about Facebook features, it spread far and fast. And like most of those assertions, it appeared to be based on a completely inaccurate inference about the site's features.
On 23 October 2017, Mashable reported Facebook's introduction of a then-new feature involving words in comments that triggered animations. Among them were "congratulations," "xoxo," and "BFF" (best friends forever):
The social network has been experimenting with these for awhile — you've probably seen them on posts with the words "congratulations" or "xoxo" (or some variation thereof.) When posted, these words appear as a different color and clicking on them triggers a brief animation (balloons or hearts, for example.)
Now, Facebook is updating the list of words that triggers these animations. Additions include: "rad," "bff," "lmao," and "thank you so much." All of those words will now come with their own colors and animation effects.
In the video below, the animation for "BFF" begins at approximately the 0:27 mark:
Although it is true that Facebook comments including the word "BFF" in green are among known animations, its appearance (or lack thereof) is not related to account security in any way. A missing green "BFF" does not indicate anyone's account was compromised ay any point, and instead most likely relates to browser settings.