Christian Page knows what it means to lead an insecure, unstructured life.
He spent over three years hanging out with this group of homeless people at the Place
Sainte Marthe in Paris.
He used to have a well-paid job as a sommelier.
But after his wife left him, he started drinking.
And when he could no longer pay the rent he ended up on the streets
"This is one of the places I slept in.
But a few weeks later, they installed these typically anti-homeless barriers.
They're placed deliberately so no-one can doss down here."
The residents are a bit ashamed of the barriers but they are glad there are no homeless people
sleeping here.
"They didn't bother anyone, but it was dirty.
I'm not sure what to think.
It doesn't look nice but at least perhaps now they are living in better conditions than
this entrance where there was lots of garbage."
Anti-homeless barriers have popped up all over Paris.
After Christian tweeted angrily about barriers that had been set up here, where people sometimes
lie because there is warm air from the metro, he was able to make a change.
"The city of Paris had put in iron rods to prevent access.
You can still see the traces.
They would have stopped people from being able to sleep there in winter when it's cold.
I posted it on twitter and the next day the city authorities removed the iron rods."
Christian posted his first tweet three years ago - after his possessions were soaked by
street cleaners.
It was winter and he wrote: "This is how the homeless are treated in Paris."
Within a few months, he had over 30,000 followers.
"I'd tweet in the morning to say hello to the planet and at night to talk about what
was going on the street.
I'd take a picture of my sleeping bag and say "good night guys", then go to bed.
And people would answer, good night, see you tomorrow.
I thought it was cool."
With his tweets, Christian was able to draw attention to the main problems homeless people
face in Paris - something his friends appreciate.
His friend Lionel doesn't have a phone.
To get one, he'd have to overcome too many hurdles that appear insurmountable to him.
"I don't even have a bank account.
I do but it's blocked.
My papers are at the lost and found office and I have to pay 11 euros to get them back
and on top of that they'll ask me for my papers.
But i don't have them."
People who live on the streets often feel like pariahs.
But Christian Page has given them a voice.
And his activism has spread beyond Paris.
People send him pictures of barricades from elsewhere in France.
This one's from Narbonne in the south.
"It's true that the social media have a certain power that can be negative for big brands.
We'll see in the next few days that Yves Rocher will certainly get rid of those barriers."
Christian is glad that his tweets can change things for the better.
His own situation has now changed for the better, too.
He has found accommodation, at least for the time being, with a Christian aid organization.