A trans activist who interned at Mumsnet (a popular UK parent's site) has leaked personal data of people who are gender critical (i.e. believe in two sexes). They posted screenshots of usernames along with IP addresses on their Twitter account (now
protected but still there). They appear to have retained this data after leaving but in any case its publication is a breach of data protection. They also bragged of having friends still working in IT there who were continuing her agenda. Posting IP addresses is not without risk.
·IP addresses can provide an approximate real-world location sufficient to narrow down where some lives.
·Be used to initiated hacking attempts.
·Identify where someone works (if visiting from there, for example)
·Cross-reference with other sites to find where else people post.
·Be used to initiated hacking attempts.
·Identify where someone works (if visiting from there, for example)
·Cross-reference with other sites to find where else people post.
Additionally, we only know what they publicly shared. It is highly likely that if they had access to users' IP Address history, they also had access to private email addresses. These can
·Contain real names.
·Contain company names
·Cross-reference with other sites or used to hack
·Contain real names.
·Contain company names
·Cross-reference with other sites or used to hack
Mumsnet have my respect and are undoubtedly working to address this. It is very hard to guard against a rogue employee. However, many MtF Trans Activists work in IT and are ideologically motivated. 
This needs to be a police matter. So far the activist has responded by setting their tweets to protected (so are still visible to their friends) and claiming it was an accident. It is not possible to screenshot user account data, retain it after you leave and post it to Twitter
by accident. We don't know what else this person may have done or what they may have shared non-publicly. Nor, given their actions and expressed attitude above, take it on trust. Action needs to be taken.
UPDATE: MN have now reported the issue to the Information Commissioner's Ofice (ICO) as expected. I honestly do not have the expertise to comment on likely consequences but my impression would be fairly light censure rather than large fines or convictions, especially
as the sharing of the IP addresses could be claimed to be accidental by her (they are in a small font at the foot of the messages she screenshotted which was the default in forum moderator view). However, the professional fallout for her could be very significant.
