I don't follow Vlad, but it's not difficult for him to pop up in my timeline. All it would take is for one of my own followers to reply or retweet him. Why does she need to block/ignore him? She's in academia, so it doesn't surprise me that it's nature to engage, and that's the entire point of twitter to begin with. A black academic telling a white man to know his place is fair and predictable, considering the source. A white man with access using his privilege to take the conversation to another level and threaten her job is also fair and predictable, because when you're a professor, it would behoove you to be artful with how you go about publicly addressing what you feel white people should/should not be speaking on. Now any backlash/fallout from him contacting Princeton is fair, which I'm sure he's considering it how he walking back what he claimed he was gonna do this morning. Black people have every right to leverage whatever power we have to protect our own, right, wrong, or indifferent.