This just happened two hours ago. I work for an IT company that services many small and medium businesses. I am in an office with about 8 to 10 other technicians. We like playing pranks and anytime one of our techs leaves their computers unlocked, you change their background to weird stuff. I had just got out of a meeting and realized a new guy left his PC unlocked. I sneaked around to his cubicle since he was just on the other side talking to another guy. I quickly pulled up Internet Explorer and googled sexy Pikachu. Found one, right clicked and set it as background. And I went in the background settings and set it to tile across the screen. Standard stuff. I quickly sneaked back to my computer without being detected and waited for him to sit back down and notice. He notices right away and we have a good laugh about it. Then he says, hey, I remote it into a client's computer. We changed their background, not mine. I shit you not. At that very moment, another tech walks up with a goofy asprin and says, hey, I have Jane Doe on the phone. She says someone to put something inappropriate on one of her computers and she wants to talk to someone about it. Jane Doe happens to be the main point of contact and decision maker for that particular client. I also believe she's the owner's daughter. At first, we thought our co-worker is fucking with us, but he's not. He's just basking in the moment of instant karma. I stand there for a good 30 seconds before I say, okay, send her over to me. I'm a director and I have a working relationship with Jane Doe, so it's really best I talk to her. I answer the phone. I listen to what she has to say. She has a mixture of confusion and anger in her voice. She attempts to describe what she felt like was an inappropriate background of a new PC and she wants to know what's going on. I tell her that one of our techs tried to prank another tech by changing his background, not realizing they were connected to a client. I apologize for that. I tell her the tech will be reprimanded and that it will never happen again. Thankfully, that was a sufficient enough response and she let it go. I hang up the phone and slap my left hand with my right while calling myself a D-Bag. I spent the last two hours getting my balls busted by my co-worker, saying things like, hey, I'm locking my computer for you or hey, I removed it into a client computer. Do you want to change the background?