That was not the only threat they received. I don't know why articles choose that statement but every one I read said "statements like..." were received.
But also the article state that they did not get security UNTIL pictures of their homes were posted. So it wasn't the threats that prompted hiring private security. It was the fact people were finding out where they live and posting their homes and addresses to the public. THAT is likely what was deemed a threat. The articles state that they received threats and online harassment.

