A character taps on your TV screen from the inside to get your attention. Yes, that's right — someone is Breaking the Fourth Wall by touching it!
As Technology Marches On, the "screen glass tap" sound effect is still in use despite being an Artifact due to the rise of flat-screen LCDs not made out of glass, though some uses now feature a "dull thump" sound effect instead to compensate for this change.
Compare with Camera Abuse, which fools with the camera, not the screen you're viewing.
- In 1991, after Bo Jackson broke his hip, Nike ran a new "Bo Knows" commercial showing him training to get back into shape. Denis Leary, the narrator, ends the commercial with a reference to his MTV promos by saying "I think you hear me knocking, and I think I'm coming in, and I'm bringing Bo and his big bad hip with me" before knocking on the screen twice.
- Mr. Opportunity from Honda commercials. In radio ads featuring Mr. Opportunity, he taps on the microphone twice.
I'm Mr. Opportunity, [knocks on glass] and I'm knockin'!
- Rix Fm ran a commercial in which the host tapped the screen of an iPhone.
- In a TV spot for Sly 2: Band of Thieves, Sly taps the screen with his cane and asks "So, uh... you in?"
- The first series of Victor Lewis-Smith's Ads Infinitum opens with an animated Victor proclaiming "Good evening, my name is Victor, I am a TV critic, and I live inside your television set." He then taps several times on the screen with his remote control, accidentally smashing it on the last tap, making him say "Oh, f-".
- Channel 4 played with this trope in its promos in the early 1990s. (At 14:14)
- After five days of "X days to go" promos for the Series 8 premiere of Doctor Who, there was one in which the Twelfth Doctor tapped cracks in the viewer's screen that formed the word "TODAY".
- LazyTown: Robbie in his Mayor Meanswell disguise takes a mallet and shatters the screen at the end of the "Fun to be the Mayor" song.
- The Office Assistant of Microsoft Office (better known by his default character appearance Clippy, though Microsoft calls him Clippit) will sometimes tap the screen. Particularly when you try to close the document with unsaved changes, in which case he leans in and taps the screen with the message "Do you want to save your changes to [document name]? [Yes] [No] [Cancel]".
- Banjo-Kazooie Before the game menu opens, the titular Banjo and Kazooie treats the player to an opening musical piece accompanied by Mumbo Jumbo and Tootie. Banjo gives the screen a playful greeting tap just before beginning.
- Bubsy, at least in the first of his games, knocked on the screen as one of his Idle Animations. In a nice little touch, the screen even ''shook'' when he did it.
- In the patient select screen of Die Anstalt, Lilo will sometimes tap on the screen with one of his blocks.
- Protagonist Rincewind does this after a few minutes of inactivity in Discworld. The screen shifts to an extreme close-up of him, and he shouts "HELLOOOOO!!" while tapping the screen and looking around for the player.
- Hugo the TV Troll: Hugo has a habit of doing this when you die in the games.
- If the player idles for too long in Ken Griffey Junior's Winning Run, the umpire will turn around, tap the screen with a baseball, and say "Play the game, kid."
- The main menu of LEGO Racers has a LEGO character (specifically the next circuit champion you have to beat) on it, dancing around. If you wait long enough, the character will bang on the screen in a sort of Continue Your Mission, Dammit!.
- In Limbo of the Lost, the hero will tap the screen to get your attention if you spend too much time doing nothing. Justified in that, unlike most video games, you are actually a character: his guardian, who is guiding him.
- Marvel vs. Capcom 3: In one of his countless fourth-wall breaking moments, Deadpool taps and shakes the screen while calling out the player for their laziness after winning a fight.
- In the CD-ROM version of The New Way Things Work, if the game is left idle for long enough, a window briefly pops up with David Macaulay trying to get the player's attention, one instance of which is this trope.
- In Pac-Man 2: The New Adventures, Pac-Man will tap the screen if you leave the game paused for too long.
- In Playstation All Stars Battle Royale, one of Jak and Daxter's introductions involves Daxter tapping on the screen while Jak stands in the background.
- Simon the Sorcerer, Simon does this to show the player he is 'getting bored' when the player does nothing for too long.
- In all of the Super Smash Bros. games, one of the possible results of having your character thrown off the top of the screen is them smacking into the camera, obscuring the view of the brawl behind them for a moment before falling off.
- The Scout of Team Fortress 2 does this in "Meet The Scout". As a neat detail, his screen-poke leaves a greasy smudge that stays on-screen for the rest of the short. This trend is carried on in both "Meet The Medic" and "Meet The Pyro", albeit being a bit of a fake-out (the "screens" he runs into ends up being a window and a camera, respectively). Even though the "Meet The Director" comic establishes that these cameras exist in-universe, it's still in line with Scout being a Fourth-Wall Observer (i.e. acknowledging that he's a character class, referring to the base as a "map", and teasing his opponents about ragequitting).
- In the Virtual Villagers spin-off Virtual Families a sick character will tap on the screen to get the player's attention if they haven't noticed the illness.
- The titular character from Zapper does this on the title screen after a randomised amount of time (sometimes not doing it at all before the game enters Attract Mode).
- Whenever the fourth wall in An Epic Comic is messed with enough, it begins to crack up.
- The German long-running micro-series Aeffle und Pferdlenote did this often... sometimes with Aeffle banging on the screen demanding that the viewers wake up, and once with Aeffle trying to wash the screen with a squeegee, only to have Pferdle admonish him that he's risking getting water in the viewer's TV.
- In the Arthur episode "You Are Arthur", Buster asks Arthur is there is someone inside his head watching everything he does on a TV screen, and he knocks on the screen producing a glass sound.
- In the opening of Beany and Cecil, Cecil licks Beany, creator Bob Clampett, and the TV screen.
- Beetlejuice: In his debut episode, Beetlejuice smooshes his face on the screen begging kids to send him money so he can get Lydia a present.
- Blue's Clues & You!:
- Blue licks the screen at the end of "Laugh With Blue. She also did it in "Happy Birthday, Blue!", "Bluestock", "Blue's Night Before Christmas" and "Blue's Show and Tell Surprise."
- Blue and Magenta both lick the screen twice in "Getting Glasses With Magenta."
- Blue also licks the screen in the show's intro sequence.
- In "Taking Care of Splatter" from Creative Galaxy, Jackson's dog Splatter licks the screen.
- Daniel Tiger Jr. will nuzzle the screen in Daniel Tiger's Neighborhood. You can hear it. Also, in "Mad At the Beach," when Daniel and Elena splash each other at the beach, they also splash the screen.
- At the end of "Staying Within the Lines" on Dragon Tales, Max ends the show by scribbling black across the screen.
- On My Friends Tigger & Pooh, at the end of the "One Big Happy Family" song in Tigger & Pooh and a Musical Too, Buster licks the screen. He also does this in the opening of the story "Roo's Kite-Tastrophy." In "Good Night to Pooh," he sniffs the screen and fogs it because it's cold and the ground is covered with snow in the story.
- In the Popeye cartoon "Battery Up," Brutus hits a foul ball that flies to the camera and shatters the TV screen.
- Used to horrifying effect in Rejected, where a stickman desperately bangs on the paper as the animated world around him collapses. It's to no avail, as he is consumed by the Dream Apocalypse.
- WALL•E: WALL•E did this in one of his movie's promos, accidentally cracking the screen.
- Tino from The Weekenders sometimes does this at the beginning of an episode, and even does it during the theme song.