This often occurs at set times, be they specific dates or times of day, depending on the location. The ritualistic hounding of the fool is steeped in history but enjoyed today by many societies.
Traditional cries such as "Fetch the Stick of Gimmon!" and "To the gimmoning pond!" would rally villagers, townspeople or housemates to the cause, and idiocy would know shame, fear, pain and spanktignation in roughly that order.
That whining sound you hear when the celebrity, who very vocally supported Brexit, finds out that Brexit actually includes them and they have to get a visa to go tour...
When Iron Maiden frontman Bruce Dickinson found that ending 'freedom of movement' for EU citizens to the UK was reciprocated by countries within the EU ending his freedom of movement within the EU, he started gammoaning very loudly on Twitter.
when you're holding up your phone and making faces at it, as though you are taking a selfie, but you're really taking a picture of the person across from you or the wall or anything else that seems interesting but you don't want to be caught dead taking a picture of.
This action is often made more convincing by wiggling the eyebrows or opening the mouth, to pretend you're trying to get a Snapchat filter to work.
FRIEND A: "Did you just take a stealthie of me?"
FRIEND B (turning phone around): "no I was just using snapchat's new filter, see?"