Please add a similar thing like "Hidden contacts" in Viber.
I mean you just need enter a short PIN-code into Opera search bar and browser will change all personal components: bookmarks, search bar history, browser history, passwords, browser look and others.
It should be VERY useful because of this reasons:
If browser is used by two or more people, it keeps big mixture of business and fun sites. And it complicates personal using for each of users.
For example bookmark bar has tens of bookmarks. Search bar history has a lot of others useless links that complicate my personal using and search speed.
Switching should be fast a safe. Another popular situation is using one e-mail service by many users in one browser. So, it's likely to keep all your passes with you. Furthermore you can "split" your accounts in other popular services just with enter a PIN.