A union has taken legal advice after ambulance managers posted details of the salaries of call centre staff on the internet.
Ambulance managers plan to close two control centres
Unison said the details were part of an explanation of plans to close sites in Worcester and Shrewsbury and relocate to Brierley Hill, in the Black Country.
It said it believed managers may have breached the Data Protection Act.
West Midlands Ambulance Service NHS Trust said no employees could be identified by the disclosure.
But it said it had now removed some details from the website.
Ray Salmon, of Unison, said the details posted on the internet included staff members' length of service, their grade, how much they earned, their date of birth, personnel number and what redundancy payment they would receive.
He said that staff were "absolutely furious," adding: "Clearly it's a shock to find that your personal details are out in the public domain.
"It's an absolute disgrace, particularly when you consider that in Shropshire we've got two reps that have been disciplined for putting information out into the public domain that we believe should have gone out there."
In that instance, control room logs were passed to the BBC which suggested ambulances were sent from Shropshire to help in Birmingham and the Black Country, reducing the number of emergency vehicles available in the county.
In a statement, the trust said: "West Midlands Ambulance Service does not believe that the information on the trust's website allows members of the public to identify individual members of staff.
"However, in light of these concerns, further information has now been removed from the table on the website to reduce still further any chance of staff being identified."
It added: "In regard to why the trust has looked at the cost of redundancies, campaigners regularly asked the trust for this information during the consultation period and therefore this data was assembled.
"The trust is still committed to making no current staff redundant; indeed it hopes to increase the number of staff it employs in its Emergency Operations Centres."