UPDATE: Facebook has told me that your friend count does in fact include some deactivated friends -
We recently changed the way we count the number of people you are friends with to include some accounts that are not currently active on the service. It is important to note, that while we are showing different counts, no additional user information will be available. Due to our internal infrastructure we can provide an even faster experience for those that use our service by showing these modified counts.
Facebook said that the reason they show you your deactivated friends on your list is so that you can defriend them and to "prevent any possible security risk posed by temporarily deactivated friends."
ORIGINAL ARTICLE: Although my Facebook Timeline says that I have 593 friends, I actually only have around 564 at the moment. It appears that the discrepancy is due to friends that I once had - but have now vanished from the Facebook landscape. You know, the ones that got away - the deactivators.
And apparently, I'm not the only one. One of my Facebook buddies recently posted a status that read "Apparently, FB did a recount today and gave me 120 new friends...WTF." Tons of other users responded with similar stories. "I got like...40 new friends," said one user. Another said, "yeah, I gained like 100 myself."
It appears that the extra friends appearing on people's friend tally are merely phantoms, sadly. You've haven't had an overnight boost in popularity - the increase in your total friends is coming from the inclusion of deactivated accounts in the figure.
One reddit user posted that Facebook was showing deactivated accounts on your friends list, to which they received a reply:
"Yep. And my friend count jumped up more than 30. I just happened to see it the other day, and saw a friend post that there number had mysteriously gone up so I checked."
A quick look at my friends list confirmed that Facebook is displaying deactivated accounts in my friends list:
Clicking on the names of one of those deactivated friends prompts this message from Facebook:
It's true that only you can see your deactivated friends on your friends list. If anyone else looks at your friends list, they'll simply see a blank whitespace where a friend should be:
Facebook explains the difference between deactivation and deletion of accounts in their Help Center.
[With deactivation], people on Facebook will not be able to search for you. Some information, like messages you sent, may still be visible to others.
We save your profile (timeline) information (friends, photos, interests, etc.), just in case you want to come back to Facebook at some point. If you choose to reactivate your account, the information on your profile (timeline) will be there when you come back.
While your former friends who have deactivated their accounts are indeed invisible to everyone but you, they are still being included in your friend count. The rash of users commenting that their friend count jumped up overnight would lead us to believe that this is something new - that deactivated friends we not always counted in your total. I've reached out to Facebook for comment and will update this article accordingly.