Why are my locked phone files accessible from a PC?

[Android Central Question]

I have a serious security issue: my phone files are accessible when it is connected to a PC with a usb cable, despite being locked. It's this way since I bought it two weeks ago and I can't find any Settings option that will allow me to change this. My previous phone (and as far as I know all android phones) used to be unaccessible from a pc when it was locked, and that's what I want with my new phone (otherwise screen lock is not actually doing anything).

 

[ManiacJoe]

Which phone?
Which version of android?
Which carrier?

You are correct in that if the phone is locked by the security screen, the computer should see no files on it until the security lock is opened.
However, once the connection is allowed, the connection is always active even if the security screen locks again, until the USB connection is dropped.