Darren Wilson, the former police officer exonerated of shooting dead black teenager Michael Brown, causing widespread civil unrest, is living in hiding and being moved from house to house under police protection.

Violence erupted in the town again following the St. Louis Grand Jury's decision not to indict the officer following the death of Brown, who was unarmed at the time of his death.

Other police officers have taken it upon themselves to voluntarily protect Wilson, while off-duty and without pay.

"Fraternal Order of Police (FOP) members from the surrounding area volunteered and have provided him with security from that time, right up until the present," FOP spokesman Jim Pasco told CNN.

"That's what the police department's supposed to do," he added, saying that Ferguson police were "unwilling or unable" to protect the officer, who recently resigned.

Wilson caught wind that his home address had begun to circulate online and proceeded to pack a bag of belongings and leave the area.

"He had to leave the grass, literally, half mowed," his lawyer, Neil Bruntrager told CNN.

"He's had to learn to live in a way that makes him completely unnoticeable," he added. He also joked that Wilson had "cross-dressed a lot".

Wilson has faced death threats by phone, email and social media.

"There were bounties that had been placed upon his life," Bruntrager said.

Legal expert Ron Hosko said that it is unlikely that Wilson's livelihood will be safe for a long time, due to the death threats, stalkers and cyber activity targeting him.

"There are cyber-activists in our world who are going to be actively trying to find out, where is Darren Wilson? They're going to be trying to find out: where did Darren Wilson spend his last dollar? - so that they can track and put out in public where he is and really create an enhanced threat to him," he said.

Wilson will have one or a couple of protection officers at a time in order to allow him to live in safety, Hosko revealed.

"Maybe one person, maybe two people, so that officer Wilson - former officer Wilson - can sleep at night," he said.