It's never a good idea to upload anything personal or confidential to cloud-based AIs, as many of them use your prompts for data collection or training purposes. If you want privacy, it's best to run LLMs locally. If a site does not state that sign-up is required, you can still use it without logging in, but you will face stricter limits and have access to fewer models.

Keep in mind that most of these will require signup, and in most cases can only generate relatively short videos.

Keep in mind many agents run in root, so it's best to avoid giving them full drive / root access to avoid any sort of issues or accidental deletions as they can modify files and execute terminal commands without permission if not set up correctly and securely. Agents also tend to have lots of vulnerabilities so it's best to not put the agent on a machine with anything important on it. Running in a container, VPS, or VM is strongly recommended.

Bypassing chatbot safeguards (aka jailbreaking) is against the TOS of most AI, so use them at your own risk.