Last year Sweden's National Social Insurance Agency (Försäkringskassan) received roughly 9,000 tips about possible benefits fraud, with 45 percent of the reports coming via anonymous tips from acquaintances of the suspected cheat.
"A typical tip is from someone who knows a person is on sick leave, but suspects the person is still working," Linus Nordenskär of the agency's control unit told the TT news agency.
Most reports are related to sickness benefits, and while 90 percent of reports to the agency are filed anonymously, only around 10 to 14 percent lead to benefits being reduced or a demand that they be paid back to the agency.
At other agencies, by comparison, action is taken in around 40 percent of reported cases.
"Anonymous tips are often a bit sparse that therefore hard to follow up. It's often more frustration than substance and in most cases, people do have a right to the benefits they receive," Nordenskär explained.
Social Insurance Agency head Dan Eliasson emphasized the agency doesn't actively encourage people to tattle on their friends and relatives.
"I'm not advocating for some sort of public snitch line to us, but if you see something wrong, it's good to get in touch," he told TT.
"We trust that most people follow the rules and do what's right."