From the letter:
We understand that media coverage of sports is changing. New media and channels for disseminating information, including ownership of distribution channels by leagues or teams themselves, require adjustments to the league/team/media partnerships that have existed for years. But the new credentials go beyond "adjustments"; they are wholesale changes that restrain our members from covering your teams in ways that serve fans without harming league interests.
Many of these changes may also violate existing law, which, in most instances, has not changed despite the advent of new media. We further believe that the real loser in this fight will be the fans, who have every reason to be wary of the SEC's actions in consolidating what can only be described as a "stranglehold" over the release of information about teams, players and games.
See the full letter and coverage.