The Rugby Football Union have won a court order aimed at finding out the identity of those selling Twickenham tickets at inflated prices through online ticket exchange site Viagogo.
Mr Justice Tugendhat said that the RFU had "strongly questioned the lawfulness" of Viagogo's practices in the past. It did not allege any wrongdoing on its part in the current proceedings, but claimed it had "facilitated or become mixed up in" wrongdoing allegedly committed by others.
The RFU's case related to 2010 autumn internationals and 2011 RBS 6 Nations matches at the stadium, which seats 82,000.
They claim that when tickets are transferred at a price higher than face value, the licence or permission represented by the ticket automatically expires or is revoked, so that the holder of such a ticket who gains entry is a trespasser. Granting disclosure, the judge, sitting in London, said the RFU plainly had a good arguable case.
He added: "It is true that the financial value of the paper on which the ticket is printed is insignificant. But the law is not concerned solely with the financial value. There are many things which have no financial value in themselves but which there are good reasons for the law to protect, for example by injunctions or by orders for delivery up.
"A ticket is like a key: it opens the door into premises. A traditional metal key has no value as metal, and a modern plastic card which can be used to open secure doors has no value as plastic. But these items have great value as means of ensuring the security of premises and goods."
He dismissed as having "no merit" Viagogo's claim that the RFU's real intention was to use publicity generated by the case to damage its business by warning off prospective users of the website.
It might well be that an order would have adverse effects upon the business but that was not a reason why he should find that that was the RFU's intention.
"I conclude that RFU has no straightforward or available means of finding out the information it seeks by this application, and that the making of the order sought is necessary."
He said he had no reason to doubt its case that such re-sales undermined its legitimate objective of promoting the sport. "The fact that this is not financial damage is immaterial in my judgment."