If I tether to my friend’s phone and log into Facebook, can my friend see that I went to Facebook? Can his mobile carrier see it? And lastly, can any of them get my username and/or password?

Does the country I’m in change the answer to any of the above?

If you can trust your friend no he can't see this. If you don't then yes he can see that you went on Facebook.

The carrier and friend can see what websites you're visiting and can likely determine who you are by that, but they can't get your username or password.

Country doesn't change this.

Answer from a Networking Engineer is yes , yes he can. Not in plan text though he would have to get access first.

by Default on most "carrier phones" no, he will need to root that phone and install bitshark or just install Kalilinux
Then your fucked.

as for Facebook, they use SSL and Tokens so your good unless he spoofs Mac and captures the token Then just redirect the traffic. But i would say your Friends do not know this

This post was edited by xJukEx on Aug 7 2018 10:19pm

So the carrier can see it regardless right?

no its encrypted and your Mac address never goes over the line. it is packaged in data link layer. even your modem adds a layer before sending it out over a WAN connection. The only way to get a Mac over WAN is do a Man in the middle attack. The MAC would be seen in the NAT network AKA Tethered. When you Tether a Network you create a mini DHCP server ( it does not tell you this it just happens). The Tethering Service would give out a NAT Address and become a gateway. .

This post was edited by xJukEx on Aug 8 2018 10:29pm