Raúl Semmler was sentenced to three days in prison for refusing to pay money to an oil company. He was prohibited from posting pictures of it on the company's social media page, but did it anyway.
"I see it as a civic duty that we keep an eye on the government," he says. He will be released on Friday (2 June) and will be given a large welcoming committee, the group says. "We're picking up Raúl from the prison," it says on his Twitter account.