I had a bad experience with Facebook Ads. There were a lot of people that were liking the advertised page, but at the end of a day, all of these people' account

I had a bad experience with Facebook Ads. There were a lot of people that were liking the advertised page, but at the end of a day, all of these people' accounts were inactive. They never actually liked or shared anything published on FB page they liked before via Ads. I have a feeling that Facebook is generating fake likes, trying to make an illusion that the campaign goes well, i.e. pushes people to spend more.