Neal Stephenson's novel Anathem has a section that talks about how the 'reticulum' (the internet, in the book's fictional world) was overrun with false copies of documents with slight changes made to them. 99.99% of all of the information on the internet was spam.
A huge industry of commercialized systems connected to the internet for the sole purpose of filling it with spam, and then the corporations would sell back filters and knowledge of which documents weren't spam to customers. Eventually, the algorithms used to modify documents developed a malicious edge, so that the thousands of spam copies of an original document would be deceptive in ways that would harm people (e.g., in Marco's electrical plug wiring example, the document would have been modified so that it could get you killed by telling you to touch the wrong wire or something.)
Inevitably, it spiraled out of control, and a sophisticated system of social trust and ranking was put in place by IT workers and systems administrators, which are a caste and race of people in the fictional world.
A huge industry of commercialized systems connected to the internet for the sole purpose of filling it with spam, and then the corporations would sell back filters and knowledge of which documents weren't spam to customers. Eventually, the algorithms used to modify documents developed a malicious edge, so that the thousands of spam copies of an original document would be deceptive in ways that would harm people (e.g., in Marco's electrical plug wiring example, the document would have been modified so that it could get you killed by telling you to touch the wrong wire or something.)
Inevitably, it spiraled out of control, and a sophisticated system of social trust and ranking was put in place by IT workers and systems administrators, which are a caste and race of people in the fictional world.
Good book. Prescient, even.