It can be a heck of a lot more convenient than doing it the old-fashioned way, but buying concert tickets on the secondary market isn't always the best way to go -- as a handful of Mumford and Sons fans recently discovered when they were turned away from a show after being caught with counterfeits.

The BBC reports that "about 100 people" were caught with fake tickets to the band's Thursday (Nov. 22) show in Portsmouth, England, as part of what's being described as a "sting" operation by U.K. law enforcement. The online ticket exchange Viagogo has been named as a primary source for a substantial portion of the fakes, a problem the company plans to address by issuing refunds to victimized fans. Head of marketing Ed Parkinson promised further action, telling the BBC, "We have to make a decision whether the seller was acting maliciously and can suspend and delete accounts."

Another reseller, Seatwave, was named in the article, and CEO/founder Joe Cohen took an equally aggressive stance in his remarks, saying that "in line with our ticket integrity policy we immediately refunded these fans in full. We are conducting an internal enquiry and will be happy to share the results."

The band will surely be interested in hearing about those results -- they addressed this incident on the group's official website, posting a message that reads, "We sincerely hope that not too many of you good honest Mumford & Sons fans have been affected. If you have purchased tickets from any secondary vendors then we would urge you to seek your money back immediately. Remember to always purchase tickets from official vendors only."