To the best of my knowledge, the Vivaldi dev's do whatever is necessary to close G**gle privacy invasions. Any that are bought to their attention that they haven't already removed, they remove.
The following post is from the Vivaldi forum, it is by their security dev (or one of them):
"yngve VIVALDI TEAM 10 months ago
There is no "spyware" involved here.
The two main reasons for Vivaldi to access Google servers automatically are:
Downloading and updating necessary components, the two major ones are the Certificate component and the Widevine video decoder. The certificate component performs extra checks on certificates, including revocation. The list of components is available on this internal page vivaldi://components
Downloading and updating the Safe Browsing blacklist. This is a so-called Bloom filter. This system works by calculating a very big number (hash) for the URL and parts of it. Then a few digits (32 bits) of these numbers are used to check in the local filter database. If the entry corresponding to the smaller number indicates that the URL may be blacklisted, Vivaldi uses more digits from the candidate number to request more information from the online Safe Browsing database, if still a possible blacklist, more data, using more digits of the number, are requested, until the server sends a list of URLs that are blacklisted. If one of the URLs is a match, then the page is block. At no time does Vivaldi send the URL to the server. The use of calculated hashes means that two almost identical URLs have wildly different hashes, but two wildly different URLs can have the same calculated hash (especially if one is using just a few digits). It is also almost impossible to reverse the calculation to get the original URL. These two points mean that it is not really possible for Google (or anyone) seeing the hash to tell which URL the user visited (in the case of the URL list, one might reasonably assume it was one of those, but it is still not a sure thing).
In neither case does Vivaldi send any cookies to the servers; only the IP address is, as always, known to the servers.
With respect to the connections to mtalk.google.com, this server is Google's Push Notifications server aka (Google Cloud Messaging, GCM). One of its uses is updates for a user's Sync data, which we are have disabled, since our Sync system uses a different system for such notification. Another use of this service is "Push Notifications" aka "Notification" from web sites. Whenever the user accepts Notifications from a website, persistent actions for receiving and handling these notifications are registered in Vivaldi, and among these actions is the establishment of a persistent connection to the GCM server, to listen for the notifications, and these connections are re-established immediately when Vivaldi starts. IOW, the connections to mtalk.google.com were initiated and configured by the user. Relevant URLs for this is chrome://settings/content/notifications , chrome://settings/siteData and vivaldi://gcm-internals
I hope this clears up some of the questions about this.
Developer and Security Expert at Vivaldi."
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