I'm not arguing that any pattern exists- I am merely arguing that we don't have enough information to demonstrate conclusively that Facebook is recommending these people as friends simply because they are all Lisas patients. Such a pattern may be probable, but there simply isn't enough information to come to a conclusion.

I don't suppose I feel it necessary to reach absolute incontrovertibility on this matter, given Facebook's longstanding history of doing things very like it, but find mere strong preponderance of likelihood to suffice. But I understand that some may feel otherwise.