Wrenching changes in the news business are starting to alter the legal landscape for journalists. The federal Freedom of Information Act and “shield” laws in many states give reporters access to official documents and offer some protections against prosecutors who demand to know their confidential sources or information that reporters have gathered. But amid catastrophic revenue declines, media companies struggling to stay afloat have less money to throw into court fights to enforce their journalistic rights. And the increasing numbers of online bloggers — including those who call themselves independent journalists — have even fewer resources. Moreover, politicians have been arguing over which kinds of bloggers — if any — should be defined as journalists entitled to free-press protections. The debate on that issue has stalled progress on a proposed federal shield law in the Senate, though backers were hopeful of reaching a compromise.