[fredsted]

> Everyone with access to your Mac can access it just as well, i assume

If they're logged on to your account, but not if they are using a different account.

>I guess it can also be read by applications, uploaded to the internet?

Not Mac App Store apps - they're quarantined.

[buster]

> If they're logged on to your account, but not if they are using a different account.

So, they are encrypted or how is that guaranteed?

[fredsted]

File permissions.