https://play.google.com/about/monetization-ads/ads/lockscreen/
“Unless the exclusive purpose of the app is that of a lockscreen, apps may not introduce ads or features that monetize the locked display of a device.”
Opera Mini completely violates this rule of Google’s Policy. And the worst: the Opera Software knows that it violates the rule, because the Opera Mini version that I'm using is from January 2018 (this month), the latest version from the playstore: https://i.imgur.com/GsNmHRR.png and https://i.imgur.com/sud0rEc.png
1A) This lockscreen ads violation is not new, you can see it here from october, 2017: http://www.techweez.com/2017/10/06/disable-opera-mini-lockscreen-ads/
1B) When we install Opera Mini, the option “Lock screen news” is enabled by default. I tested it on my smartphone. You can see the result: https://i.imgur.com/nvzIjNw.png https://i.imgur.com/378zd04.png https://i.imgur.com/VW5jj9G.png https://i.imgur.com/bGR6cIF.png https://i.imgur.com/qVA2ne6.png https://i.imgur.com/7s13mzi.png https://i.imgur.com/vebLZnJ.png https://i.imgur.com/tzixHEF.png https://i.imgur.com/3fOPxih.png https://i.imgur.com/ELzo1OL.png
https://i.imgur.com/rzEuyIw.png https://i.imgur.com/1aVva8L.png https://i.imgur.com/2cVn8CL.png

Do you think it can not get worse? Yes, it can.
You could find the option “Lock screen news”, that is enabled by default, right?
Theoretically, although they violate the google rule, the user can manually disable this option in the settings, right? Basically just look for “Lock screen news” in settings.
In brazilian portuguese “Lock screen news” is “Notícias na tela de bloqueio”.
Okay, when it shows the option, it perfectly: https://i.imgur.com/vOnIMnY.png and https://i.imgur.com/5NvtR6t.png
But when the Opera Mini maliciously hides this option from its users? So they can not disable this option in the settings? https://i.imgur.com/pZlnKn6.png
Yes, it only shows the “Lock screen news” option when the user starts using the app, so Opera Mini has collected few data about him. After a few days using the app, the “Lock screen news” option will simply disappear. (obviously for the option to come back, so I would be able to take out the printscreen, I deleted the data + app cache from Opera Mini, so the lock screen option came back, as if I were a new user).

Do you think it's over? No.
Now this problem is from Opera Mini and Opera browser:
https://play.google.com/store/apps/details?id=com.opera.mini.native and https://play.google.com/store/apps/details?id=com.opera.browser
If you look for Privacy Statement website in both websites from Playstore, it indicates this website: http://www.opera.com/privacy
It says “How do we protect your data? We treat your personal data as required by law. We are a Norwegian company and we follow Norwegian data-security laws as well as other national legislation, as needed.”
But what if I told you that user data (from Opera Mini and Opera Browser) is being sent to China? Yes, when user enable Data Saver mode in both browsers, it connects to a vpn in China. Opera Mini: https://i.imgur.com/S5NDIwi.png and Opera Browser: https://i.imgur.com/CwQguw7.png