As AI chat assistants increasingly hold sensitive context, including saved conversations, connected tools, and memory of personal and work details, account takeover on these platforms has become a real exposure, and TechCrunch published a walkthrough of how to check whether accounts on ChatGPT, Claude, or Perplexity have been accessed by someone else. The practical value for builders and IT-security practitioners is in the platform-specific mechanics, since each service exposes session visibility differently. ChatGPT surfaces an Active Sessions panel under Settings, Security and Login, letting a user spot unfamiliar devices and revoke either a single session or all of them, and it supports traditional password resets alongside multi-factor authentication. Claude, by contrast, has no password at all; Anthropic authenticates purely via emailed login links, so its equivalent Active Sessions list under Settings, Account is the only lever available to terminate suspicious access, and there is no password-reset step to fall back on. Perplexity is the least transparent of the three: it does not expose a session list, so the only remediation path is a blanket sign-out of all sessions, followed by re-authentication via a one-time email code. For engineering and security teams standardizing incident-response playbooks or writing internal security-awareness guidance, this is a useful reference because AI platforms are increasingly treated as high-value targets. Attackers who gain access can exfiltrate proprietary code shared in chat history, pivot through connected integrations, or impersonate the account holder in agentic workflows. The piece is a reminder that account-security hygiene, such as unique passwords in a manager and MFA where available, needs to explicitly extend to AI tooling, not just traditional SaaS and email accounts, and that incident-response steps differ meaningfully across providers because their authentication models are not standardized.