If it's sitting in your browser's cache, how do you determine wether it's there unsolicited or not? That's the problem already with real-time ad brokering. And

If it's sitting in your browser's cache, how do you determine wether it's there unsolicited or not? That's the problem already with real-time ad brokering. And it's easy to set any images to "display: none" with CSS, but they would still be loaded in the background. Now explain that to a court.