Long time, 10+ year client facing Nielsen employee here who is currently working their last few weeks here before being let go. I have never once been in any kind of trouble, have had outstanding client relationships, and have always gotten glowing reviews at performance review time. I have been very happy the majority of my career here.
However, once I found out that I and rest of my team was being terminated, I intentionally started supplying clients with ad tracking tags that I knew had bad code in it.
These clients would later email me asking for troubleshooting meetings to fix the errors I created on purpose (but they didn't know that). The data they were getting was broken and unuseable. I ghosted them. No response from me at all. They would follow up with "Please advise!" Each email angrier and more desperate than the last.
They would CC my supervisor, but my supervisor didn't care, and just told me to delete these email and ignore the clients plea for help. They all fully understood that Nielsen was in chaos at the moment and likely just chalked it down to that.
The bad tags I sent them will absolutely lead to useless broken data that they won't pay for. These are big contracts too with high profile NYC ad agencies. Oh well. Not my circus, not my monkeys.
I would say what I did will easily cost Nielsen 7+ figures in revenue since I started doing this, and many more clients are out there right now are using the junk I sent them and won't know the impact until months from now. And of course this will damage the relationship Nielsen will have with these clients in the future. My boss knows and was actually supportive of it. We even laughed about it over a few drinks.
I also intentionally taught my replacements bad practice and inaccurate information that will hopefully leave a lasting bruise once I'm gone.
Anyway, hi KR and the rest of the C-Suiters who might read this! Have a nice day.