There are many ways for which most of the same benefit can be gotten, such as having the software be paid for by each school, which would host it itself and mai

There are many ways for which most of the same benefit can be gotten, such as having the software be paid for by each school, which would host it itself and maintain its own database. Crawling from the web would still be feasible (just with a lot of duplication of effort between universities), and you would still be able to catch students at the same school who copy from each other---and most of the students who copy from others are going to copy from students who attend the same institution.