Matt Andrews
Software engineer making apps – that aren’t apps – and more at the FT. 会说汉语.

How Chinese ISPs put adverts on your website

So Chinese ISPs silently wrap your website in an iframe, then float an advert in the bottom corner over your content.

This causes a number of JavaScript errors and warnings…

20+ cross domain security warnings… Yet another reason to use a modern browser…

After spending hours measuring performance almost line by line to ensure the web apps I contribute to are optimised for speed (not including this site, which is a just-add-water WordPress installation), having it dumped inside an iframe and forced to run along some shoddily written and non-minified JavaScript libraries is a little disheartening.

This is way more advanced than merely blocking an URL. I wonder how else they are able to read, rewrite and manipulate web content…

Serving the website over SSL stops the adverts from appearing.