In this paper we explore the concept of "accessibility as a service" by proposing a cloud computing service to help deaf people to access digital contents. The proposed service automatically generates and embeds a sign language video track into multimedia contents. The service organizes the collaboration of sign language experts to dynamically adjust the system that runs on a cloud computing infrastructure. As a case study, we made an implementation of the service for providing support for the Brazilian Sign Language (LIBRAS) and some preliminary tests with Brazilian deaf users to evaluate the proposed solution.