As reference I can give you Wikileaks
) and the privacy statements of the respective companies, for example Cisco (OpenDNS)
, with pretty wide open statements, like "We may share personal information (...) if we believe disclosure is in accordance (...) or (...) with law enforcement officials, government authorities, or other third parties as necessary to (...) meet national security requirements (...)"
Google is the only one of those three who is saying they do not sell or share DNS data. That's only SAYING (they could still DO it anyway), but still slightly better - and for DNS-historic reasons, one COULD maybe trust them a bit on this one. The other two are pretty much guaranteed to share their DNS data with all kinds of agencies (if not BEING them). Obviously, also your own ISP's DNS servers technically have the same issue, but that
The privacy concern is this: imagine a Greek person making subtitles, translations. To make his translations as well as possible, he always does research about the theme of the movie he is subtitling. Now he is making subs for a movie about moslim terrorism, and so he is visiting fundamentalistic fora, web sites about explosives, etc., using OpenDNS or Cloudflare. After that, he goes on a holiday to USA. You think immigration will just let him in?
It's not anymore like "nothing to hide, nothing to fear"... I would just advise a (paid) VPN - and at least a VPN provider NOT based in USA/CAN/UK/AUS/NZ (Five Eyes spying) nor one that pays (a lot) to affiliates (fake reviews).
Anyway, I didn't mean to pollute your topic about Subber with these thoughts. I just thought it was not an extremely good idea to advice those DNS servers.
My two cents