A Derby man prosecuted for erecting a protest banner has been ordered to pay £1,706 in court costs.
Richard Butler and his banner for the Derby Heart group
Richard Butler, 45, claimed the sign on his Kedleston Road home was to save part of his garden from a road project.
But the banner carried contact details for a pressure group fighting plans to widen the road outside his home.
At Derby Magistrates' Court on Monday he was convicted of displaying an advert without consent and given a 12-month conditional discharge.
Mr Butler had denied the charge.
Warning the ruling would have implications for protesters everywhere, he said the people of Derby should be disgusted by their council's actions.
Mr Butler said: "It's obviously not the verdict I expected and although I have to respect the law, I feel that I
have the moral judgment in that the magistrates gave me a conditional discharge.
"We will have to consider whether to make an appeal but I am very, very sad that the city council have used advertising law to suppress opposition to their road scheme."
He had been protesting about Connecting Derby, a city council road scheme which will widened roads around the Five Lamps junction - a congestion hotspot.
The 8ft-wide banner read "Save Five Lamps - Derby" and was hung from the window of his home.
An action group, Derby Heritage and Environmental Association for Residents and Traders (Heart), has been fighting the plans for two years.
District Judge Joanne Alderson said the inclusion of Derby Heart's logo and phone number breached advertising laws and "invited public support".