; and (ii) may not be used to create or contribute to a profile of the user from which it is collected. (3) Exceptions (A) Law enforcement The prohibitions on data collection described in paragraph (1) shall not apply where data is collected for the purpose of assisting a law enforcement agency. (B) Complementary services Notwithstanding paragraph (1), a first-party operator of a covered website, service, or application may collect additional data from a user beyond what is necessary for the operation of such website, service, or application if such additional data is necessary for the operation of a different covered website, service, or application that is— (i) both owned and operated by such first-party operator; (ii) designed to complement the covered website, service, or application accessed by the user; and (iii) branded as a complementary website, service, or application to the covered website, service, or application accessed by the user. (c) Interfering with DNT signal It shall be unlawful for any person to— (1) block or impede the ability of a covered website, service, or application to receive the DNT signal; or (2) block or impede the ability of a connected device to send the DNT signal. (d) Discrimination based on DNT preferences It shall be unlawful for a first-party operator of a covered website, service, or application to— (1) deny a user access to, or service from, such website, service, or application on the basis that the website, service, or application received the DNT signal from the user