(CNN) -- For much of the world, February 14 is known as a day to celebrate love. 

But in Iran, Valentine's Day has come to mark another occasion as well—the anniversary of the house arrest of Iran's leading opposition figures Mir Hossein Mousavi, Mehdi Karroubi and Zahra Rahnavard. On February 14, 2011, Iranian authorities placed Mousavi, Karroubi and Rahnavard under house arrest for calling on Iranians to demonstrate in support of the popular Arab uprisings across the region. 

According to Reuters, earlier this month Karroubi was moved from a Ministry of Intelligence-controlled safe house to his own home. 

The transfer shined new light on the plight of Iran's "prisoners of rights"— those imprisoned for seeking to exercise commonly recognized political, social, religious, economic, and cultural rights, denied to them by the Iranian government. 

In addition to opposition politicians like Mousavi, Karroubi and Rahnavard, Iran's prisoners of rights include lawyers, journalists, professors, students, labor union workers, poets, musicians, artists, dissident clerics, bloggers, ethnic and religious minorities, LGBT persons and even humanitarian aid workers. 

Civil rights and human rights activists are also a primary target. Some prisoners of rights, like women's rights and student activist Bahareh Hedayat, have been arrested for holding gatherings to protest laws that discriminate against women. 

Others, like the "Yaran"—the seven leaders of the Bahá'í religious minority in Iran—are imprisoned for teaching a faith the Iranian government does not recognize. 

Still others, like lawyer Abdolfattah Soltani, are imprisoned for their efforts to assist or seek justice for prisoners of rights. Ironically, before his arrest, Soltani had been preparing a case in defense of the seven Bahá'í leaders. 
Who was their lawyer?
Abdolfattah Soltani