Tag badges were recently awarded. Pardon my ignorance, was there a recent change/announcement that I may have missed? Did a script fail earlier? It appears to have been awarded in bulk:
1 Answer
This is the result of a network wide bug with tag scores and associated badges. It was fixed yesterday, Stack Exchange developer @Taryn wrote quite a lengthy explanation about it. At the moment, it's unclear whether the badges will be redated to their original date or not.