Have you heard of 'Phynd', 'Flatlan' or 'Direct Connect'?The recording industry has stepped up its campaign against music swapping at higher education establishments, filing suit against four students who operated file-search services on colleges' internal networks. The lawsuits, filed against two students at Rensselaer Polytechnic Institute (RPI), and one each at Princeton University and Michigan Technological University, ratchet up the pressure that the Recording Industry Association of America (RIAA) recently has been putting on universities to block campus file-trading. The trade group still has not filed suit against average file-swappers who use more common services such as Kazaa, however. "The people who run these [campus] networks know full well what they are doing - operating a sophisticated network designed to enable widespread music thievery," RIAA president Cary Sherman said in a statement. "The lawsuits we’ve filed represent an appropriate step given the seriousness of the offence.” University students have been widely viewed as the core of the various file-swapping networks ever since the appearance of Napster on the digital scene in late 1999. Universities have seen half or more of their network bandwidth used by people uploading and downloading songs, software and movies over the past few years. Colleges have attempted to crack down on the practice of file swapping in various ways, ranging from blocking network traffic associated with Napster or Kazaa to confiscating computers used to trade files. In a recent congressional hearing, some lawmakers called for criminal prosecutions for campus file-swappers. In its lawsuits, the RIAA compares the use of the campus search software - variously called 'Phynd', 'Flatlan' or 'Direct Connect' - to the defunct Napster service, dubbing the services "local area Napster networks". In fact, the technology used by the three pieces of software varies widely, sometimes looking very different to the old Napster model. Direct Connect resembles Napster most closely, allowing users to connect to a central server, search one another's hard drives and download files from one another. Flatlan, by contrast, lets a student set up a search engine - often on an ordinary dorm room PC - that scours all computers connected to a campus network that have Windows file-sharing turned on. Unlike Napster or Kazaa, which helped create a network of computers that would not have existed otherwise, Flatlan searches a network that already exists. Phynd is a generic search engine technology that lets users configure it to search whatever they want, including FTP sites, websites or local files such as those found on a college network. 'Dan', a university student who runs a Flatlan-style server but has not been sued, said the RIAA is missing critical differences in the file-sharing technologies. He asked that his full name and the name of his university not be used. "With or without these services, people would be able to share these files," the student said. "It's Microsoft that's allowing people to share these files. We're just accessing public information." That difference in technology may or may not have any effect in court, lawyers say. "It does seem like all it's doing is indexing resources that are available on a network that people are already a part of," said Fred Von Lohmann, an attorney with the Electronic Frontier Foundation, a digital civil liberties group that has defended file-swapping companies in court against the RIAA. "It doesn't seem like there's anything wrong with building a tool to do that. And it doesn't seem like there's anything wrong with running that tool." Where the students could run into shadier legal territory is when those indexes and search results come back loaded with MP3 files, Lohmann said. According to the RIAA lawsuits, several of the students also maintained archives of hundreds of songs on their own machines. The RIAA said that the difference in technologies didn't matter. The differences are "irrelevant from a copyright perspective", said RIAA Senior VP Matt Oppenheim. "All of these are networks created for one purpose and are being used for infringement." All the lawsuits were filed in federal court. The RIAA had not contacted any of the students before filing the suits, Oppenheim said. John Borland writes for CNET News.com.