Fifa is warning football fans that they are likely to be scammed if they attempt to buy tickets for next month's World Cup tournament in South Africa from unauthorised websites.
Ticket scams are now a major headache for almost any event, and music and sporting events are the most common targets. But that hasn't stemmed the tide of willing victims for one of the simplest crimes going.
Specifically, Fifa draws people's attention to a recurrent emails which claim users have won tickets in a prize draw and which require upfront payment.
Other scams include bogus websites, fraudulent travel package firms and individual touts trying to offload tickets they almost certainly do not possess.
Paper tickets are expected to find their way on to the back market as the tournament nears.
Perpetrators typically set up bogus websites, or spam people with barely-convincing emails claiming to have access to tickets.
That the website looks professional means nothing, including any accreditation it might claim to have.
A major problem is how people distinguish what is authorised form what isn't.
Confusion over this basic issue - and the fact that tickets to events are now controlled by middle-men most users have no direct relationship with - is how the bogus ticket industry has grown up in the first place.
According to Fifa, tickets other than those sold through packages can only be bought from the organisation's website, fifa.com, or in South Africa from the national football association.
An official list is available on the organisation's website, however, the supplied link led to a 404 error when we tested it.
Alternatively, if in doubt, the organisation can be emailed at firstname.lastname@example.org. What users should do only at their peril is buy from eBay sellers.
"Not every potential fan may be aware of the repercussions (not just to himself but to the wider activities of the tournament organisers) of purchasing tickets, ticket inclusive travel packages or hospitality packages from unauthorised sources," Fifa said.
See also: Symantec website exposes World Cup scams