Why does android start downloading data via Loader after screen on-off?

Question

Android

In onCreate I call data loading via

getLoaderManager().initLoader(ID_LOADER, null, this);

Everything works fine, and most importantly, when the screen is rotated, there are no repeated calls to Loader. But as soon as the screen goes out, when it is turned on, the data is loaded again. How to turn it off? Are there standard tools?