Rape Crisis Dunedin educator and funding co-ordinator Anna-Kristy Munro said the page was "exploitative, demeaning, and degrading to women".
"We believe that the sexually abusive nature of this Facebook page is an example of the underlying current of rape culture that exists within the Otago University campus."
The page has outraged many on campus, with more than 2500 people - mostly female Otago University students - joining a second page, called "Rack Appreciation Awareness".
Otago University Student's Association vice-president Ryan Edgar said the second page had unfairly targeted some people - himself included - who were added to the group without giving their approval.
Asked whether there was a "rape culture" at Otago University, he said: "The underlying issue of female objectification is a serious issue and cannot be ignored, but we also reject the notion that all males involved in this are sexual predators."
Acting Area Commander Dunedin Clutha Waitaki Inspector Mel Aitken said a woman had come into Dunedin police station to speak about the website.
"We have talked with her and provided her with the appropriate advice." Police were not investigating the page as sharing an explicit picture of an ex-girlfriend without their consent "may not be unlawful of itself", she said.
"Every case needs to be assessed individually but in general terms it depends on the content of the photograph and circumstances in which it was taken."
She urged people to be careful when sending images or information over the web.
Asked if Mr McDonald was being spoken to as part of its investigation, an Otago University spokeswoman said: "A male student will be contacted in relation to this matter. The university does not identify individuals who are the subject of disciplinary investigation."
On Monday, Mr McDonald told members of the group he was shutting the page because of legal concerns. "The Titanic has sunk. We had our fun while it lasted lads but we just cannot carry on and put ourselves at risk with the law."
On Tuesday, he defended himself in a post on his Facebook page, saying the page was created "out of respect and nothing less".