Lecturers are facing a wave of student activism over teaching quality, which academic leaders have likened to "bullying".
Student campaigners at the University of Central Lancashire have posted examples of bad feedback online. At the University of Bolton, students have left anonymous cards in staff pigeonholes, giving them marks out of ten for performance.
And at Manchester Metropolitan University, students are texting its students' union to inform it when classes are cancelled or lecturers are late.
The University and College Union is unhappy about the campaigns, and it has likened the scorecards at Bolton to "hate mail".
At its annual congress last week, the union passed a motion on the subject that said: "(UCU) notes the concern regarding evidence, particularly in the North West region, of unsolicited, inappropriate and often anonymous criticism by students of academic staff via text messages, social networking sites and pigeonhole postcards. Conference believes that this is a form of bullying (that) cannot be tolerated."
The campaigners insist that they simply want to ensure students receive the best teaching.
Mark Higgins, president of the University of Bolton Students' Union, said the point of the anonymous scoring "wasn't to upset staff, but to make them realise that feedback is important. If they received a seven, they'd have no idea how to get a nine - replicating the experience of a student who receives a score and nothing else," he said.
Despite the UCU's condemnation, there is anecdotal evidence that the campaigns may be having an effect on the way students are taught at the affected institutions.
Mr Higgins claimed that Bolton was changing its guidelines on feedback as a result of the action, although the university denied that this was the reason.
Meanwhile, Uclan is producing a student guide to assessment and feedback, and is asking staff to record audio feedback for students in personalised podcasts.
The National Student Survey showed that 43 per cent of Uclan students were dissatisfied with the feedback they received.
Examples of poor feedback are not hard to find.
Kathryn Ecclestone, professor in education at Oxford Brookes University, said she knew a professor who, when pushed for feedback on an MA thesis, simply said: "Thin."
"Another in an old university politics department told me that he often puts a line through students' essays with phrases such as 'tedious drivel'. In many post-92 universities, this sort of feedback would be the basis for formal grievances."
She added that dissatisfaction with feedback was running at an "all-time high".
Professor Ecclestone, who has just completed a two-year research project on assessment practices in further education, said students increasingly expected feedback to demonstrate that lecturers respected their efforts and were showing personal interest.
Meanwhile, lecturers are becoming more nervous about student reactions to feedback, couching advice in terms such as "I wish you had ...", she said.
Wes Streeting, president of the National Union of Students, said that the introduction of top-up fees had led to a growing consumer mentality among students.
"They want to see a substantial improvement in the student experience as a result of their investment," he said.
'WHEN DID ACADEMICS DECIDE THAT HIGHER EDUCATION WAS NOT ABOUT THE STUDENTS?'
When news broke of the Bolton students' campaign on www.timeshighereducation.co.uk, it led to robust online debate.
"How terrible that poorly performing academics should finally be held to account," said one anonymous student. "Students pay more than £3,000 a year for minimal contact time, bad feedback and shoddy lectures - when did academics decide that higher education was not about the students?"
An academic respondent said: "Strangely enough, I ask my students to (provide anonymous feedback). It hadn't occurred to me that I should get 'extremely distressed' by their opinions."
However, another said: "The students' union is openly inviting and giving its endorsement to students to engage in the spiteful and vindictive treatment of individuals."
One academic from the US, where student evaluation is more common, sounded this warning: "Many junior colleagues, instead of teaching as they believe, start teaching with the intent to receive good evaluations. This often leads to grade inflation."
Another reader said: "It's not the academics who want to restrict student contact time, or who don't want to give feedback. Rather, the system is constructed in such a way as to restrict what they are able to do."