DataLith is local-first and it doesn't go to any server so everything stays in your computer so you don't have to worry about your data leaking however that's how the original version of DataLith is and since it's open-source you could modify it and use it anywhere however you like.

If you happen to find any security issues or vulnerabilities please email the details to me at arminnxm@gmail.com or otherwise you could just fix the issue yourself and create a pull request and I will then merge it.