Likes created by fake accounts or people without real intent are bad for people on Facebook, advertisers and Facebook itself.
Facebook has a strong incentive to aggressively go after the bad actors behind fake likes, because businesses and people who use Facebook platform want real connections and results. Businesses won't achieve results and could end up doing less business on Facebook if the people they're connected to aren't real.
It's in Facebook best interest to make sure that interactions are authentic, so Facebook has a number of teams that detect fraudulent activity and shut it down.
Facebook works to ensure that the connections between businesses and people are genuine and meaningful and want to share the resources that Facebook has to help you understand where fake likes come from, the defences that Facebook has in place and tips on how to safeguard yourself against fraudulent activity.
What are fake likes?What are fake likes?
When Facebook team refer to fake likes on Facebook, they explicitly referring to external services that sell packages of likes from fake accounts or people without real intent by offering a certain number of likes for a flat fee. Fake like peddlers tempt Page admins with offers to "buy 10,000 likes!" or other similar schemes. Facebook doesnt referring to likes obtained using the free or paid fan acquisition tools offered by Facebook, which provide legitimate likes garnered from people with a genuine interest in a Page.
How and why inauthentic likes are generated
There are four primary ways in which fake likes are generated:
1- Click farms, in which individuals with real accounts on Facebook are paid to manually like specific Pages
2- Fake accounts that do not represent real people and are generated for the primary purpose of liking Pages
3- Self-compromised accounts, in which a person knowingly installs malware or gives up control of their account in order get more likes for their own Page
4- Compromised accounts that have been infected with malware, causing the accounts to like Pages without the knowledge of the account owners
People behind these fraudulent activities are rational actors with clear financial motivations. They make their profit by promising and generating Page likes to admins around the world who typically don't understand the negative implications of purchasing these likes.
How Facebook detect and prevent fraudulent activity
Selling likes created by fake accounts or people without real intent is only profitable when it can be done at scale. To make it more difficult for these scams to be profitable, Facebook abuse-fighting team builds and constantly updates a combination of automated and manual systems that help them catch suspicious activity at various points of interaction on the site, including: registration, friending, liking and messaging.
Facebook write rules and use machine-learning to catch suspicious behaviour. When Facebook team catch fraudulent activity, they work to counter and prevent it – including blocking accounts and removing fake likes.
Source : Facebook for business