Amanda Silberling at TechCrunch:
Numerous Twitter users are reporting a bug in which Circle tweets — which are supposed to reach a select group, like an Instagram Close Friends story — are surfacing on the algorithmically-generated For You timeline. That means that your supposedly private posts might breach containment to reach an unintended audience, which could quickly spark some uncomfortable situations.
I observed this bug when a tweet from someone I follow appeared on my For You timeline, but the retweet button was disabled, despite the person’s account being public. When I clicked on the tweet, it disappeared. I asked the tweeter if that post was intended for their Circle — which I am not in — and they confirmed this was the case.
I’m starting to think the folks running Twitter don’t really know what they’re doing.