Cracking down on college students, the music industry is sending thousands of more complaints to top universities this school year than it did last year as it targets music illegally downloaded over campus computer networks.

A few schools, including Ohio and Purdue universities, already have received more than 1,000 complaints accusing individual students since last fall — significant increases over the past school year. For students who are caught, punishments vary from e-mail warnings to semester-long suspensions from classes.

The trade group for the largest music labels, the Recording Industry Association of America, identified at the request of The Associated Press the 25 universities that received the most copyright complaints it sent so far this school year. The trade group long has pressured schools to act more aggressively against online pirates on campus.

''It's something we feel we have to do,'' RIAA President Carey Sherman said. ''We have to let people know that if they engage in this activity, they are not anonymous.''

The top five schools are Ohio, Purdue, the University of Nebraska-Lincoln, University of Tennessee and the University of South Carolina. The RIAA complained about almost 15,000 students at those 25 universities, nearly triple the number for the previous school year.

''They're trying to make a statement,'' said Randall Hall, who polices computers at Michigan State University, seventh on the list with 753 complaints. Michigan State received 432 such complaints in December alone, when students only attended classes for half the month.

Hall meets personally with students caught twice and forces them to watch an eight-minute anti-piracy DVD produced by the RIAA. A third-time offender can be suspended for a semester.

''I get the whole spectrum of excuses,'' Hall said. ''The most common answer I get is, 'All my friends are doing this. Why did I get caught?'''

At the University of Massachusetts at Amherst — which received 897 complaints — first- and second-time offenders receive escalating warnings about piracy. After a third complaint, the school unplugs a student's Internet connection and sends the case to a dean for additional punishment.

The music group said each university should set its own penalties for stealing songs and said campuses are rife with such thefts. ''When we look at the problem, it's particularly acute in the college context,'' RIAA chief executive Mitch Bainwol said.

The music group said popular software programs it has targeted at schools include AresWarez, BitTorrent, eDonkey and other programs that operate on the Gnutella and FastTrack services.

Under federal law, universities that receive complaints about students illegally distributing copyrighted songs generally must act to stop repeat offenders or else the schools can be sued. The entertainment industry typically can identify a student only by his or her numerical Internet address and must rely on the school to correlate that information to trace a person's real-world identity.

Some schools aggressively warn students after they receive complaints. Others don't. Purdue, which has received 1,068 complaints so far this year but only 37 in 2006, said it rarely even notifies students accused by the RIAA because it's too much trouble to track down alleged offenders. Purdue said its students aren't repeat offenders.

''In a sense, the (complaint) letter is asking us to pursue an investigation and as the service provider we don't see that as our role,'' spokesman Steve Tally said. ''We are a leading technology school with thousands and thousands of curious and talented technology students.''