A Garden City resident challenged city officials after he found personal documents in a dumpster at a city recycling center.
Anthony Manetta found tax statements and water bills with names, addresses and phone number. But Walker said he found information in the dumpster that was even more alarming.
"Checking accounts, with names, where the bank is, their savings accounts and their routing numbers and this is not public information that I'm getting from the city manager," Manetta said.
Security experts say that kind of information can be used to commit identity fraud.
Manetta took his concerns to Monday's Garden City Council meeting, telling council members what he found and asking about the city's document shredding policies.
When Manetta thought his concerns were not taken seriously, he protested. Walker was removed from the meeting.
Garden City mayor Randy Walker said the matter was investigated. It was learned a city worker inadvertently put classified information into a recycling bin.
"It's unfortunate but I will tell you the city took immediate action. The city manager met with the employees and changed policies and procedures so this will never happen again," Walker said.
On Tuesday, Garden City workers went through all the recycling bins and shredded anything that looked sensitive.