Many students take out loans of up to £9000 annually for university, which are supposed to be repaid once the student has left university and is earning more than £15000 annually. Some students know that they will not be going on to getting a job, or atleast not working at a job which pays £15000. Thus, they know that they will not be able to pay the loan back, and have no intention of paying it back. Is this permissible?