Not trying to defend Facebook, but they did not do it on purpose. They developed a really addicting social network where you do as many interactions as possible

Not trying to defend Facebook, but they did not do it on purpose. They developed a really addicting social network where you do as many interactions as possible. When Facebook started it was a different world: Almost no data privacy laws, internet security in its infancy (e.g. in 2008 HTTPS was a rare new thing, not cross-origin security etc.) and people were spamming Farmville notifications to each other. It just turned out that this structure is an excellent ground for lots of bad things.