[Air-L] About social media data availability

[Xanat Meza]

Hello everyone!
I have a situation with some social media data we collected for a paper that is currently under revision.
The situation is complex because we collected this data from a Facebook group dedicated to a rare medical condition back in 2017, when social media data rules were not as strict as they are now. When we requested ethics review from our institution, they even told us we did not have to do anything in particular and got the study approval without much difficulty. 
Therefore, we requested permission to the group administrators to collect posts, posted a permission request for the group members, asking them to send us a message if they wished to opt out from the study, and collected one thousand posts by hand. We noted that there were many researchers in this group and that the members participated in surveys and medical studies frequently and with enthusiasm, so we thought at that time that an opting-out format would be enough. The data basically consists on user name, the texts in the posts, date and time of the posts, number of replies, and reactions. We separated the user names and replaced them with alphanumeric codes.
Now, a reviewer of our paper is insisting that we MUST share this data openly because it is anonymized. However, we think that it should be available upon request, as social media data management has become stricter in recent years, particularly on the case of data from vulnerable communities. If we place this data related to a rare medical condition in an open repository, even people who are not researchers may have access to it and use it to bully this Facebook group, even if in theory, they could not target specific users. 
Does anyone have any ideas or advise on how we can respond politely to this reviewer that it is safer for everyone to keep the data available upon request? 
Xanat V. Meza

Ph.D. Kansei, Behavioral and Brain SciencesUniversity of Tsukuba
M.A. Media and Communication
Yeungnam University
B.D. Graphic Communication Design
Universidad Autonoma Metropolitana