I'm sorry if I don't ask this on the right site, but there isn't any site related to Git.
I want to store my personal data on GitLab *(even if GitLab is essentially for sharing source code)* to serve as backup and to sync it between my computers, and prevent data loss.
I want to know if this is really secure and I can trust GitLab and send all my data to it.
can I trust GitLab?
Short answer: No. Trusting Gitlab is one thing, but trusting all the employees of Gitlab having root access to the servers is very different.
Real answer: Nobody knows.
For a sad story, read: GitLab account hacked and repo wiped, then ask yourself if you wish to be in the same position as that poster.
When your files are in the cloud, you are basically exposed to an attack by all the hackers in the world. I wouldn't call that secure.