A public art installation in Canada has been delayed over fears it would promote hate speech and profanity.
Toronto's Transit Commission (TTC) has declined to turn on a digital artwork display in a new subway station that feature words typed by commuters.
The decision was made days before the new station opened over concerns commuters might abuse the platform.
The artists behind the project say the TTC's alternative solutions do not align with the installation's message.
The C$500,000 ($399,000; £294,500) installation, entitled LightSpell, would allow commuters to type eight-letter words - including special characters and numbers - on keyboard terminals. The messages would subsequently appear on digital displays throughout the station.
The German art studio behind the project, realities:united, call the work a "super sculpture" that serves as both functional indoor lighting and an art installation in the Pioneer Village Station.
"Any wording - however rude, stupid, offensive - will inevitably also be the light source serving the demands of the community of other waiting people," the studio said on its website.
"Everyone is asked to overwrite, correct, or answer the existing message. Messages might be erased after 10 seconds or last weeks."
The piece is "an experiment in public interaction".
Transit authority spokesman Stuart Green said on Thursday the main concern for the transit authority is hate speech, an issue that was raised when the artwork was tested in the weeks before the station opened.
He said that while concerns had been previously discussed, "the issue of public art became secondary" as the TTC focused on completing the major $3.2bn subway extension.
The TTC proposed two options to tackle profanities: a blacklist with automatically banned words, or a white list that would only allow pre-approved words to be posted.
Tim Edler, one of the Berlin-based artists behind the project, said he opposes the blacklist as impractical and "wrong from a conceptual point of view".
He dismissed the white list proposal as "more like North Korea than Canada".
But Mr Edler said he is "a bit glad" this debate is happening because the artwork itself is about navigating free speech in a digital world.
He thinks the transit authority can still be convinced to turn on the installation and run the "experiment".
"Hopefully in a year we can find we can trust people," he said.
Mr Green says that while the ultimate goal is to have the installation switched on, the TTC is looking at other options.
The matter will be brought before the TTC board on 18 January.