Consider your tree as a part of an Internet forest or, preferably, an Internet orchard. For the tree to survive, there must be at least one link to your root. Try pressing this JTT button to see how it works. Many designers place return buttons at the end of a page to return after reading the page. Our placement at the top of a page provides an instant view of the current location on the tree immediately after reaching the selected page.
Nobody casts anything on the Internet.
In fact, Internet is the first system ever implemented, without any central authority. So far, no anarchy has emerged.