The NewsGuild union says disparities tend to be smaller at newspapers that have long been unionized.
Reporters from alt-weeklies and local newspapers are trying to cover a crisis that is causing layoffs and closures across the industry.
Executives of the combined company, which will keep the Gannett name, acknowledged there will be layoffs.
Greg Burton accused union sympathizers of "surveilling" other journalists, saying that's something he'd expect of a murderer or child molester.
GateHouse Media announced it is buying USA Today owner Gannett Co. for about $1.4 billion, which would make it the largest U.S. newspaper company by far.
The list includes McClatchy, AOL, HuffPost, Yahoo, BuzzFeed and Gannett.
If nothing else, Gannett's $864 million takeover bid has exposed Tribune's farcical operations under chairman Michael Ferro. But instead of Titanic hitting the iceberg by accident, Ferro is aiming for it.
Gannett said it made an offer to buy Tribune Publishing on April 12 for $815 million, including the assumption of $390 million of debt.