The Ecchi Effect, or "Beals' Law" states that for any given Google image search, provided safe-search is off, there is a high probability of at least one example of ecchi/hentai material included in the search results, no matter the obscurity of the terms searched for.

This effect has been attributed variously to the following factors:

1: The ubiquity of such material on the intarwebz, especially in bulletin board posts that devolve into chan sessions.

2: The fact that deep down you really wanted to search for "pre-teen anime panty shots", but didn't have the honesty to do so. Google knows better. Don't try to fool Google.

The Ecchi Effect can also be regarded as a consequence of Rule 34.