From The Times:
'United have been allocated 6,000 tickets, but with only 19,000 tickets purchased by Everton season ticket-holders — about 7,000 fewer than usual — more tickets have been available on general sale. Fans’ forums for both clubs have featured messages suggesting United fans have been able to fool the Ticketmaster ordering process by posing as Everton supporters.
David Harrison, the Everton club secretary, insisted that "everything had been done" to ensure tickets did not get into the wrong hands.
"The problem we have is geographical," he said. "While it would be easy to differentiate the majority of Arsenal fans from Everton fans simply by their postcodes, it is likely that just as many United fans as Everton fans live in areas like Wigan, St Helens and Cheshire, which makes it impossible to differentiate.
"Ticketmaster ask which team a supporter follows, but if someone is prepared to lie to obtain a ticket there is nothing we can do."
Harrison also said the evening kick-off had not helped. "The 5.30pm kick-off does not help the situation, but the FA has a commercial agreement with the broadcasters and they understandably want to air their best games at the times that best suit them," he said. "We don’t anticipate any problems."