I was accused of distributing porn on work networks.
I was preparing a server for migration new hardware, so thought it a good opportunity to clear out old files. I was checking a file called "calendar" was a current on-call or outage list or anything, and it opened a naked woman on my screen. We were expected to report porn we found, so I dutifully did so, after deleting it, and sent a request for the backup to be deleted as well, as I didn't have enough access to do so.
Next thing I know is a disciplinary for gross misconduct. Fortunately my union rep was brilliant, pointing out it was right to investigate, but shouldn't have gone any further than that.
I'm still bitter they thought I'd be that stupid, especially as I have previously been involved with HR investigations to gather log evidence for people who actually were looking at porn at work.
It was also noticeable that I, the only woman in the department, had to go through this. I never got an apology, nor any acknowledgement of my right to work in a respectful, porn-free environment, and the main culprit had previously left the company. Plus a colleague who had used the n-word in a call at the time this was going on, in front of witnesses, just got a mild discussion with his manager not to do it again. No disciplinary for him.
All the fuss they make about things like a respectful work environment, and wanting to attract more women to work in tech... and the next day was a focus on mental health in the workplace. That felt a bit hollow, after they had unnecessarily put me through about the most stressful thing I'd had to deal with at work.