From airplanes to restaurants to Walmarts, certain places just attract more troublesome Karen behavior than others. As evidenced by the post office Karen we covered last week, any place related to the mail is at high risk. This UPS store and its manager found that out the hard way. 

"You're discriminating against a very innocent woman," the God-loving Karen says at the start of the video. "I follow the 10 Commandments." Based on what comes next, that's pretty hard to believe. 

"My sister is a serial killer and someone is going to come kill you," she shouts before listing serial killers. 

"Duality of man," the Reddit user GoForthandProsper1 commented, highlighting the hypocrisy of her two messages. 

"I don't think your sister would appreciate you snitching on her like that," Cautious_Vanilla8620 joked. 

But while the Karen's behavior left much to be desired, many viewers felt that the UPS worker's response was far from professional.

"I think that was probably a battle of two previously undefeated Karen's," @RFC1871Bob stated on Twitter. "They both had that confident swagger."

If there's one takeaway from this, it's to be careful the next time you're getting ready to mail a package. You never know when a Karen will show up to the store with you.