Dionysus Park caught the attention of Andrew Ryan because it clashed heavily with his ideals. He sent Stanley Poole to spy on The Family (those devoted to Sofia Lamb) and gather evidence to show that The Family was more than just a religious group. Poole succeeded and Lamb was arrested. He then took control of the park, throwing massive and wild parties. When Lamb returned from prison, Poole flooded the park to prevent Lamb from learning of what he did there.
During the mission in Bioshock 2, Stanley has the player take care of every Little Sister, as they posses memories of what he did.