Save from Proxy

The place where I browse net is not a safe place any more I am not the
system administrator here probably our admins intercept the traffic
that is going via proxy I doubt this because number of times when I
tried to log in to some of my mails I got a message Site Identity not
verified I guess that might be a problem because of a fake SSL
certificates (might be expired authority certificate) or what soever be
the reason I could never trust to the site that I am connecting
neither I can not trust my Network Admins it has become a serious
problem
now ,I would be thankful if some one could tell a solution to my
problem I use Linux only and there are no super user previleges to me
what can I do to save my self
because of this problem I have stopped browsing

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