Is Stream.Read buffered when doing network I/O?

Question

So I was recently doing some work, when somebody told me that if doing a Stream.Read on a network stream that is obtained from calling one of .NET's GetResponseStream on a WebResponse or those are buffered.

He was saying that if you were to put a breakpoint, in the code where you're reading, you wouldn't stop the network traffic. I find that bizzare, but also hoping that it's true. How does that work? Is it even accurate?

using (Stream webResponseStream = this.webResponse.GetResponseStream())
{
   byte[] readBuffer = new byte[bufferSize];
   int bytesRead = webResponseStream.Read(readBuffer, 0, bufferSize);
   while (bytesRead > 0)
   {
        bytesRead = webResponseStream.Read(readBuffer, 0, bufferSize);
        // If I put a breakpoint here, does network activity stop?
   }
}