On social media, legislators and supporters of gun safety reform are using the hashtag #enough to share updates on the filibuster.Murphy, who was elected just before the 2012 Sandy Hook School shooting that killed 26 people, is calling on Congress to pass legislation to prohibit suspected terrorists from purchasing guns and to require universal background checks.As he spoke, Murphy referenced Congress’ failure to pass any legislation in the aftermath of Sandy Hook, according to the AP. "For those of us that represent Connecticut, the failure of this body to do anything, anything at all in the face of that continued slaughter isn't just painful to us, it's unconscionable," he said.Early on Sunday morning, a lone shooter armed with a semi-automatic rifle killed 49 people at Pulse nightclub in Orlando, FL, in the largest mass shooting in U.S. history. In the aftermath of the attack, many people were appalled to discover that though the shooter had been twice investigated by the FBI for a suspected terrorism connection , he had been allowed to legally purchase the gun he used to attack the LGBTQ nightclub.