Jeff Jarvis at BuzzMachine equates supporting journalism "at its source" with crediting "competitors" and also are colleagues in the trade.
"Link unto others as you'd wish they'd link unto you," he quips.
He critizes not just Google and online packages of news that don't fully cite sources, but problems with and by the Associated Press.
Read his short but snappy essay here -- http://www.buzzmachine.com/2007/09/13/support-journalism-at-its-source/