This is really only true for unencrypted communications. Of course in most cases you still let onlookers know about which websites you're connecting to, which is usually enough to get an idea of what you could be doing. Still, these problems can be solved using things like I2P, Tor or Freenet. If you run the latter in its 'dark mode'*, anyone overseeing your communications can't even see you're doing anything.

* It's high time software developers stop calling the most useful parts of their software shady names. Why does it have to be dark? I'm not doing any shady business, I just don't want everyone to know about it.