A group of teenagers sparked a police inquiry in Merseyside after posting footage of themselves posing with weapons on the internet.
A number of hooded youths appear in the video
The montage of clips, entitled Seacombe Ladz, shows hooded youths brandishing a kitchen knife, baton and pellet gun.
Merseyside Police - dismissed as "scum" in the two-minute video - investigated after one shot helpfully lingered on a street sign in Seacombe, Wirral.
Four males were arrested on suspicion of firearms offences.
The two 15-year-olds, 16-year-old and 20-year-old were later released on bail, Merseyside Police said.
As well as the weapons, the video features two "guard dogs" - a pair of tail-wagging collies.
One of the participants also appears to be wearing an electronic tag that looks like one issued to released prisoners.
In addition to the featured street signs, a Merseyside Police logo doctored to read "Merseyside Police R Scum" appears.
Insp Paul Farrar, of Merseyside police, said: "Any information that suggests unlawful use or possession of firearms, or other offensive weapons, will be vigorously followed up and investigated.
"This includes videos posted on the internet," he added.
The YouTube clip has been viewed more than 530 times but has failed to impress those who sat through its running time.
One reads: "Seriously! tht is so embarrisin!! get a grip! think ur hard with a pellet gun! PLEASE!"
Another comment said those responsible "should be ashamed of themselves".