"Please stop doing this s**t. It is not safe for you and it is mean to people who don't know any better," Eilish wrote, alongside a screenshot of one of the many YouTube videos featuring different content creators also pranking random people by impersonating the singer.
Eilish also shared multiple screenshots of the slew of different videos on YouTube featuring similar stunts, and wrote simply, "please stop."
Eilish also called out the clothing in which the impersonators chose to represent her style.
"Also soooo disrespectful that you'd go out pretending to be me wearing THIS," she wrote over a closeup of one impersonator's drab, grey knee-high socks.
The YouTuber who was responsible for the video Eilish called out specifically, Jordan Matter, responded to the video shoot after a strong response from Eilish's fans.
He also took to Instagram to explain what his intention was, alongside a photo of the Eilish impersonator -- who is also an acrobat -- doing an aerial flip on a pier, surrounded by onlookers.
"Hello everyone. You’ve been commenting on the video shoot I did yesterday, and I’d like to respond. I gathered a crowd and had an acrobat pretending to be Billie do a huge cheer flip, which revealed it was not Billie. I had absolutely no intention of disrespecting Billie. I’m a big fan, like everyone else," Matter wrote. "I’ve never done a celebrity impersonation video before, but they’re pretty common so I thought it would be fun to add my own acrobatic twist. I felt it was completely harmless since at no time in the video are we pretending that she is actually Billie."
ET's Kevin Frazier spoke with Eilish backstage after nabbing her final big win -- and fifth win over all for the night -- and the "Bad Guy" singer had a hard time wrapping her head around the monumental triumph.
"I'm dying, man. I don't know, this s**t is crazy. Who am I?" Eilish said with a dazed laugh. "This is surreal. This is like a dream…. I'm speechless."
Check out the video below to hear more from the acclaimed performer.