Here, give me your hand.
Mainly a visual joke, asking a person to hold out his hand with the intention of handcuffing and arresting him.
When a person joked about something problematic, something that will cause trouble with the law if actually realized (e.g. committing bank robbery for steam games) , use this to light-heartedly "warn" the speaker.
Some exceptions exist, but no hard rules in the world of memes. Generally, use the FBI OPEN THE DOOR meme (Yes, the FBI meme, works in China too.) for pedophilia jokes, and express delivery/water meter hoax meme for politically incorrect jokes.