Tompkins said the breach in trust cracked the wall that protects news organizations from the intrusion of its sales teams trying to sell advertising or generate profits.
"The 'wall' exists whether it's real or imaginary," Tompkins said. "We can debate about how high the wall should be or how permeable."
The reversal of a wall "breach" in which the editorial side of a news organization uses information from the business side is a rare occurrence compared with, say, content influenced by advertisers.
For example, Tompkins said no credible newspaper should use subscriber information to inform its reporting.
"Could the news side use business records to find someone's address or cell phone number?" he asked. "Would they be able to know your credit card information if you paid for your subscription service by credit card?"
Another concern springing from the recent news about Bloomberg is the power of large, diversified media companies to use data from its own business divisions.
Tompkins pointed to the widespread fear from the European public after media conglomerate News Corp. used private investigators to tap cell phones in 2002.
"This doesn't approach that yet and I hope it doesn't but I think there is a rightful concern about how peoples' privacy is used or abused by media companies, especially as media companies grow larger and larger and touch all parts of our lives," Tompkins said.
ABC News' Rebecca Jarvis and Zunaira Zaki contributed to this report.