SAN FRANCISCO — As health workers on the front lines of the coronavirus pandemic plead for personal protective equipment, volunteer efforts to create hand-sewn masks and deliver them to medical professionals have quickly sprung up across the internet.

But those efforts were hampered by Facebook’s automated content moderation systems over the past week, according to sewing organizers who have used the social network to coordinate donation campaigns.

Facebook’s systems threatened to ban the organizers of hand-sewn masks from posting or commenting, they said, landing them in what is colloquially known as “Facebook Jail.” They said it also threatened to delete the groups. The issue has affected do-it-yourself mask makers in states like Pennsylvania, Illinois and California, they said.

Facebook has long struggled to distinguish between innocuous and malicious content on its site. While the Silicon Valley giant has relied on automated systems to flag and remove posts that violate its terms of service, those systems can have trouble spotting nuance and can sometimes be overly aggressive or make mistakes in identifying what may need to be taken down.