How does it relates to synchronization? By the way, you can already password protect your synced data.
To avoid people having access to Opera and any other software or data in your computer, just use a password to login into your OS and add users for others to use it when needed.
Each global problem has to be address as a Pinned Topic.
This is the right management - despite any opinion or "experience" -.
Users has to be educated if they are not, ten first users will learn the right way if they are "corrected", then, some of those 10 users will educate the new ones, those "second" new users will do the same, etc...
At the end of a month +/-, good practices will be learned by all.
If not, you have the chaos that currently is the Opera's Forum.
The current behaviour is a waste time, unnecessary clicks, search, typings, space...
Also, it gives a very bad image.
As far as it's possible, similar topics may be being merged. Lots of them about VPN issues were already merged into a single topics/plataforms.
The Official explanation is not Pinned as a global topic explanation, and the same question/problem is asked/reported every day and every time in many different topics.
As I've said, it quite easy to undestand.