Perplexity's AI search engine, which allows users to engage in chat sessions with Google and Meta without their knowledge or consent, is accused of sharing massive amounts of sensitive information with third parties. The lawsuit alleges that even paid users with the "Incognito Mode" feature have their conversations shared with personal information, which can be accessed by third parties like Google. The complaint also criticizes Perplexity for not disclosing its secret use of ad trackers.