In the report, he stated that the 'extension is essentially a copy of Adguard extension for the core code, and essentially a copy of ABP for the user interface aspect', and that he thought that Firefox users donating to extension developers would surely want to donate to the original developers.

Raymond Hill, creator of uBlock Origin and uMatrix, reported the AdBlock Ultimate extension in 2017 but nothing came out of it. The AdBlock Ultimate extension has more users than Adguard currently Adguard has about 322k users, AdBlocker Ultimate 418K. RÃ©mi found mentions of AdGuard throughout the code of AdBlock Ultimate that suggest that code was copied from AdGuard. The code of the extension is very similar to AdGuard, a very popular content blocking solution. Why is recommending an extension which seems to be a copy-pasting from another extension and potentially in copyright infringement? claims to be open-source and GPLv3 so I installed and checked the sources using the debugger. published the following message on Twitter today: One of the recommended extensions, AdBlocker Ultimate, appears to be a copycat extension.

Adguard extension firefox