Update: Here is the MIT banned presentation.

A federal judge on Saturday granted the Massachusetts transit authority’s request for an injunction preventing three MIT students from giving a presentation about hacking smartcards used in the Boston subway system.

The Electronic Frontier Foundation, which is representing the students, anticipates appealing the ruling, said EFF senior staff attorney Kurt Opsahl.

The undergraduate students had been scheduled to give a presentation Sunday afternoon at the Defcon hacker conference here that they had said would describe “several attacks to completely break the CharlieCard,” an RFID card that the Massachusetts Bay Transportation Authority uses on the Boston T subway line. They also planned to release card-hacking software they had created, but canceled both the presentation and the release of the software.

U.S. District Judge Douglas Woodlock on Saturday ordered the students not to provide “program, information, software code, or command that would assist another in any material way to circumvent or otherwise attack the security of the Fare Media System.” Woodlock granted the MBTA’s request after a hastily convened hearing in Massachusetts that took place at 8 a.m. PDT on Saturday.

EFF staff attorney Kurt Opsahl said that the temporary restraining order is “violating their First Amendment rights”; another EFF attorney said a court order pre-emptively gagging security researchers was “unprecedented.”