I hate to recommend anything to do with lawyers, but isn't this a perfect job for them? If an
ISP takes someone's web page and alters its content before serving it up, they are surely
creating a derived work for commercial gain, in flagrant violation of the owner's copyright.
We aren't talking a few lines of symbol definitions in a million lines of system. We're
talking about plagiarism of an entire work and them deliberate misrepresentation of the
authorship and origin of the bastardised version!
So set up a web site, with copyrighted material. Make it necessary for the users to accept the
copyrights explicitly (sign up, read, all modification strictly verboten, click OK). Get a
tame user to browse and obtain evidence of the derived works. Then sue! Possibly even for
libel, rather than copyright violation. Adding adverts, possibly containing malware, could be
highly damaging to the copyright owner and/or the owner of the website serving the copyrighted
material without the adverts).
Note the adverts might inadvertently cause offense or outrage through mis-targetting. "First
picture of motorcyclist shot dead on motorway" alongside a motorcycle advert tagline "Nobody
ever wished they stayed in more". An advert for a mobile phone called a "Blast" alongside what
later proved to be an erroneous report of a man killed by an exploding mobile. Such is
unfortunate, but the ads were placed there by an organisation invited in by the copyright
owner. Imagine if not. Also the ads might contain malware. ISPs beware. You could get sued
from both sides (copyright owner and browser user) at once!
And finally, consider the ISP's customers. If my ISP starts doing this I'll immediately take
my custom elsewhere, and make a small-claims claim for the cost of being forced to do so. Some
customers might also be able to sue for larger damages, if for example they are already
post-processing web pages for themselves (loading share prices into databases and suchlike)
when such post-processing is broken by an ISP choosing to alter the HTML in transit.
All in all, it's a really dumb idea for the ISPs. I can't imagine it'll catch on, they'll be
making themselves into large and ill-defended targets if they do.