The website was shut down Wednesday morning with only the message "Hackeado por HighTech Brazil HackTeam" and a list of apparent hacker names: No/One, CrazyDuck, Otrasher and L34NDR0.
"We're checking into this," Village Administrator Anthony Giaccio said, adding that the village did not have a timeline of when the website would be back online.
Sleepy Hollow's website includes important announcements from the village, upcoming municipal meetings, village regulations and community events.
The website had been updated by 10:30 a.m. Wednesday to say it was undergoing maintenance.
Giaccio said he did not know why someone would hack the website.
"Who knows?" he said. "Maybe it was the headless horseman."
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