> which let you use any compatible client Which means that third-parties can easily capture large parts of the "friends" graph with just a small number of user

> which let you use any compatible client Which means that third-parties can easily capture large parts of the "friends" graph with just a small number of users consenting to give them data. You're also now entrusting your communications to whatever clients other people are using without any chance/need for you to consent to their privacy policies.