TORONTO -- After running for almost three years, a popular New York subway sticky note installation is under fire after the artist behind it was handed a US$25 citation for posting signage in the subway system.

The interactive installation is called Subway Therapy and aims to “help people smile, laugh, and feel less stress,” according to a website by founder Matthew Chavez.

It consists of a wall of pastel sticky notes stuck to the square tiles of the underground tunnel connecting two New York City subway lines. Commuters are encouraged to take a sticky note, write down a message and stick it up on the wall in response to prompts like “What makes you happy?” and most recently “How are you really?”

That most recent installment of the installation led to the citation, Chavez told CTV News Channel on Wednesday. While he wasn’t “super shocked” to get the ticket, Chavez thought it was “a bit odd” considering he’s been doing the installation for years without getting one. Otherwise, it was “par for the course.” He’s been kicked out of transit stations all over the world, including in Berlin and Brussels.

“I’m doing something that technically isn’t legal,” he said, adding that he’s already paid the fine. He won’t fight it since he never asked to set up the installation. After reaching out to subway operator Metropolitan Transportation Authority, Chavez believes the citation was simple “miscommunication.”

“From what I’ve heard it was sort of a perfect storm… It went through several different channels and eventually ended up with the officer that came to give me the citation. My hope is it won’t happen quite that way again,” he said.

Commuter Maddie Jurisich told Spectrum News NY1 that she appreciated the installation, which she described as a “very beautiful,” sight during a transit where colour is scarce.

Jurisich said it makes her “feel so grounded and connected with other people even though it’s all anonymous.”

Chavez started the sticky note installation in 2016, after U.S. President Donald Trump was elected, as a way to give people an outlet in the post-election turmoil.

The MTA said in a statement that the station staff ordered the sticky notes removed because some contained lewd, offensive and profane language.

In an Instagram post from the official Subway Therapy account, Chavez wrote that “I don’t want to censure people’s expression generally but I do take down hate speech when I see it.”

He told Spectrum News NY1 that “one of the notes that they pointed out was ‘feeling lit AF’, I think was one of the notes.

“It’s pretty innocuous, I think,” he said.

Chavez said that he thinks “this work is really important.” On Instagram, he added that he hoped this “isn’t part of a larger trend to scare away creatives from public space.”

The MTA and NYPD have been criticized recently for what has been called a disproportionate crackdown in the underground. A viral video captured earlier this month shows officers handcuffing a woman for selling churros in a subway station -- and in October, a video of an arrest in the underground showed panicked commuters scrambling out of the way before more than 10 officers descended on a single man in a subway car, after allegedly drawing their guns on the packed platform.