A recent article on Ars Technica highlights how easy it is to high jack and/or interfere with the content that you post on the net. This time it was the internet providers posting ads as they passed on the requested URL's. The ads interfered with the information on the requested sites sometimes covering whole paragraphs and covering up the paid advertisements of the website.
And when initially confronted with this issue by customers, the internet providers stated that the ads were being added to keep costs down for customers as opposed to lining company coffers.
But when reminded of the copyrights of the altered websites the internet providers thought better and discontinued the practice.
Internet sites and postings require constant vigilance---especially when even the trusted providers provide the hacks.