You can easily transmit information hidden in web requests. If I own a web server at somedomain.com I can run code that asks for somedomain.com/someencryptedinf

You can easily transmit information hidden in web requests. If I own a web server at somedomain.com I can run code that asks for somedomain.com/someencryptedinformation.html, and I'm sure that someencryptedinformation will appear in the server logs. Automate encoding something in that string and you can send data using simple web requests that won't trigger anything looking for connections on non standard ports. And what if connecting to domain A followed by B within 2 seconds is translated as a 0 and the other way around as a 1? You can, albeit slowly, send whatever you want just by alternating those two connections. Yes, just contacting the outside is sending information.