After Facebook launched its new Marketplace feature — read: Craigslist competitor — on Monday, people quickly noticed that the service wasn't exactly being put to its intended use. Rather than used furniture, bikes, and appliances being put up for sale, people posted offers purporting to sell guns, animals, and weed, among other prohibited items.

Facebook now tells the BBC that "a technical issue" stopped its review system from catching these violations. "We are working to fix the problem and will be closely monitoring our systems to ensure we are properly identifying and removing violations before giving more people access to Marketplace," Facebook said. "We apologize for this issue."

The problem appears to be resolved now, with few spam results present and none of the obviously illegal or banned listings showing up. At least one listing for a tobacco-related product, all of which are supposed to be banned, did make it through to the Marketplace listings Facebook displayed me, however.

Barring major technical errors, it seems like it should be possible to filter out most banned product listings from the Marketplace since they're all listed publicly. Craigslist, for instance, sees its share of spam but is not widely flooded with prohibited items the way Facebook was on Monday.

What Facebook has had more trouble with is sales made in private, through hidden Facebook groups. Gun sales have continued to happen this way despite Facebook's prohibition. At least on the Marketplace, Facebook ought to be able to maintain those intended constraints.