They say they do: “Messages on her phone revealed she planned to smuggle the materials through customs without declaring them. She knowingly broke the law and took deliberate steps to evade it.”
> The article left me with a couple questions - is cancelling a visa for not declaring something like frog embryos normal protocol?
A visa like J-1 can be cancelled at the port of entry for a variety of reasons. Doesn't mean she immediately loses her status. With a visa like that you're essentially at the mercy of the State Dept. You can still reply but you have to exit the US. The normal procedure would have been to immediately send her to Russia. The idea is, you go back to your home country and re-apply. But they didn't do that and "let her" stay in detention since Russia is a dangerous place for her.