Before revision: However, the 2013 mass surveillance disclosures revealed that the GCHQ gathers "raw" information (without filtering out the communications of British citizens) from the web as part of its "Mastering the Internet" programme.
After revision: However, 2013 mass surveillance disclosures revealed that the GCHQ gathers "raw" information (without filtering out the communications of British citizens) from the web as part of its "Mastering the Internet" programme.