These kinds of modifications aren't just used to block ads - they're also key to accessibility. People who have photosensitive epilepsy or who (like me) suffer from low-contrast vision problems use add-ons to reformat pages so that we can safely and legibly access them.
WEI's creators said they were only trying to put the web on a level playing field with apps, which routinely rat you out to the companies you connect to.
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