The Zahir was an idea conceived by Jorge Luis Borges... an object, image, sensation, or idea that, once encountered, engenders helpless obsession in the subject. At first, the subject thinks of the Zahir frequently, then constantly, and finally can think of nothing else. The idea consumes the mind, and memory is annihilated; nothing remains but an idiot consciousness, contemplating the Zahir.
As you browse the internet, you encounter images. Ideas. As the contents of the internet grow exponentially larger, the chance that it contains your Zahir approaches certainty.
You're probably safest if you just stick to porn.