I see it Safari 7 still. Try Firefox. Apple got rid of Activity window, more dumbing down. In Firefox the bottom left of the window shows what is hanging and the Stop button stays lit to press.
In Safari the page seems like it loads but the X stays in the url field on the right.
Now it's "Connecting to forums.MacTech
.com" or "Transferring data from p.rfihub.com"
Hangs on the iPhone too, the gear keeps spinning next to the network icon on the left and the url bar has an X in it for a couple of minutes.