Posters promoting a cannabis oil firm landed a businessman in court.
And Luca Di Gennaro ended up before magistrates thanks to his incriminating Facebook profile picture.
Cardboard adverts for Infusion CBD were dotted across Newcastle in a bid to drum up business for the Whitley Bay firm.
However, they caught the attention of a Newcastle City Council enforcement officer, who investigated the sign's origins.
He tracked down the firm using the Instagram links displayed on the signs, and eventually found Di Gennaro's personal Facebook account.
"From that, he managed to see from his main profile (picture) was the same logo which matched that of the logo on the banner," said council prosecutor Jill Loftus.
Magistrates ruled Di Gennaro had erected the signs illegally - and fined him £1,000.
Newcastle Magistrates' Court heard the adverts had been tied to railings throughout the city centre as well as in Chillingham Road.
On the Heaton street they were crudely put up on a traffic island and the court was told had the potential to "cause a distraction" to drivers.
The signs were put up last September and October, advertising a firm which boasts on its Instagram page that it is the "UK's most trusted CBD".
The store sells the oil - which is legal - in various formats, including capsules and even sweets.
The court heard officials eventually tracked Di Gennaro and sent him a warning letter.
However, he ignored it - and simply put up more signs.
"No permission was sought from Newcastle City Council place these notices anywhere in the city," said the prosecutor, who said the act was illegal unless permission was granted beforehand.
In total, fall five charges of contravening a regulation or enforcement notice were found to be proved.
The 28-year-old defendant didn't turn up to court, and has yet to respond to a request for comment.
However slamming his "persistent" offending, magistrates ordered him to also pay an extra £355 in court charges and costs on top of his four-figure fine.
