The filter was put in place at approximately 10pm PST (pacific standard time) on Sunday, a Napster representative said. Napster attorney David Boies announced the plan to implement filtering software during a hearing in a San Francisco District Court on Friday. The filtering software lies between the end user's computer and Napster's servers, so that although a user may have one of the blocked songs on his or her hard drive, other users searching for the title would not be able to see it. However, as Napster has warned, one of the flaws of the system is that it can filter out only exact file names; songs with file names that have been misspelled or made up by users won't be blocked.
Given that Napster's search engine can track down song titles even where a name is slightly misspelled or altered, this left users able to access some songs that were supposed to have been blocked. The Napster representative provided the names of three songs that are on the filtering list. Two of those three songs could still be accessed by users Monday afternoon..
Metallica's "Enter Sandman," for example, was easily attainable without needing to modify the search query. Over 100 users were offering the song on just one of Napster's servers under titles including "Inner Sandman," "Enter the Sandman" and simply "Sandman."
Another song on the filter list, Billy Joel's "Piano Man," was available on the same server, listed under "Joel, Billy" followed by the title "Piano Man" or "PianoMan." The song had apparently not been blocked because Billy Joel's name appears in reverse in the file name.
The third song, Metallica's "The Unforgiven" from the same 1991 album as "Enter Sandman," could not be found even after several attempts on different servers.
"The filtering engine has to be limited by definition, or else it would block out more songs than intended," said Malcolm Maclachlan, an electronic media analyst with IDC. "I think everybody knew that there would be a cat and mouse game between the users and the filtering service."
A larger question is whether users actually need Napster any more, given the growing level of awareness around alternative file-swapping services such as Gnutella, OpenNap and Freenet.
"I don't think (the filtering software) is really that relevant," Maclachlan said. "Thanks to the media coverage, every Napster user knows the name of a half dozen other sites they could try," he added.