2) (in internet culture)
a) To be close to or to break the TOS of a social media site in a way that is eye catching to some. Especially used if the action that caused the user to glow is something the community they are a part in often get criticized for.
b) To be suspected of being a federal agent who is either trying to infiltrate or provoke online communities. Often posted when an account is found to have doctored photos, made up first and last names, and/or relatively extreme ideas. Possibly a reference to the quote, "The cia ******* glow in the dark."
1) Becky: "How do I look?"
Samantha: "Omg, you're glowing!"
a) User1: "All parents who vaccinate their children should have their children taken by Child Protective Services."
User2: "This man is glowing so hard."
b) User1: "If you're being interrogated by the police, I'd recommend to not invoke the right to remain silent because it looks more natural to the judge."
User2: "User1 is glowing so much, all of the images they've posted of themselves we're ripped from someone's abandoned blog from 2006 and nobody has been recorded in the US of having the same name they claim to have."