> Facebook’s desktop sitewide changes will then make ad content indistinguishable from non-advertising content. For blockers to get around these changes, Facebook said they would have to begin analyzing the content of the ads themselves, a costly and laborious process.<p>Is it really that costly and laborious? Just take the hash code of the image and see how many users have already marked that hash code as an ad.<p>Not trivial, but also not difficult.