I have been reading the UKRI webpages on research using online data, including social media.
The most obvious point is that it says that researchers need to abide by the regulations set by the data producers. As has been said many times, MN’s terms and conditions are very clear that data scraping is not allowed. So I would consider the UKRI pretty authoritative on what is or is not ethical, and that is a clear stumbling block for Eden. MN have asked for the dataset to be deleted; Aston have refused.
This leads to a fundamental ethical problem, that users are not aware how their data is being used because they assume such use (data scraping) is prohibited by the terms and conditions. Therefore it is not possible to argue that users consent (because they do not know). The issue of identifiably is not relevant yet, because the research does not get past the issue of consent.
There is also the question about what constitutes privacy in a forum such as MN. It seems to me recognised in writing about internet research that traditional understandings of public space do not hold in social media research - that is to say, that forum and social media is used by people who have a reasonable expectation of privacy in so far as their words will not be used for research but simply read by other users of that forum or of their social media. I think this interlinks with the consent piece - so people write for other users of MN and as such, consent for their posts to be read in this context (as well as being used within MN’s terms and conditions re copyright).
The other key problem seems to me - as others have said - is that the forum posts being used cover children and situations about children, and indeed other vulnerable groups (so additional ethical issues), and that by triangulating posts from published quotes, users may indeed be identifiable to those who know them. There is no way of guaranteeing this would not happen. I identified the mum of a friend of my DD as a poster on here by a phrase she said her son used about an exam. Knowing that anecdote, my DD would identify me on here. That’s a banal example, but it makes clear the issue.
I know I am only saying what has already been said, but what little I have read of the ethics form suggests that none of the complexities of this have been properly considered.