In an article on the liberal website Minbar Al-Hiwar Wal-'Ibra (http://www.menber-alhewar1.info ), reformist Saudi journalist and human rights activist Wajeha Al-Huweidar described Saudi Arabia as "the world's largest women's prison." She added that unlike real prisoners, Saudi women have no prospect of ever being released, since throughout their life, they are under the control of a male guardian - their husband, father, grandfather, brother or son.
Huweidar and other women activists recently launched a campaign against the Saudi Mahram  Law, which forbids women to leave their home without a male guardian. She told the Kuwaiti daily Awan that the campaign, whose slogan is "treat us like adult citizens or we leave the country," was officially launched at the King Fahd Bridge, connecting Saudi Arabia and Bahrain, where the women demanded to cross the border without a guardian. 
The following are excerpts from Al-Huweidar's article: 
Prisoners Can Be Released From Prison - But Saudi Women Can't
"The laws of imprisonment are known all over the world. People who commit a crime or an offense are placed in a prison cell... where they serve their sentence. [When they complete it], or get time off for good behavior, they are released... except in cases [where a person is sentenced] to life imprisonment or death. In Saudi Arabia, there are two additional ways to get out of prison early: by learning the Koran or parts of it by heart... or by getting a pardon from the king on the occasion of a holiday or a coronation - after which the prisoner finds himself free and can enjoy life among his family and loved ones.
"However, none of these options exist for Saudi women - neither for those who live behind bars [i.e. who are actually in prison] nor for those who live outside the prison walls. None are ever released, except with the permission of their male guardian. A Saudi woman who committed a crime may not leave her cell when she has finished serving her sentence unless her guardian arrives to collect her. As a consequence, many Saudi women remain in prison just because their guardians refuse to come and get them. The state pardons them, but their guardians insist on prolonging their punishment.
"At the same time, even 'free' women need the permission of their guardian to leave their home, their city or their country. So in either case, the woman's freedom is [in the hands of] her guardian."
Prison Inmates Are Stripped Of All Authority Over Their Lives - And So Are Saudi Women
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"As is customary in prisons throughout the world, inmates are stripped of all authority and sponsorship over their own [lives]. All their movements are monitored and controlled by the jailor. The prison authorities decide their fate and see to their needs, until the day of their release. This is also the usual situation of the Saudi woman. She has no right to make decisions, and may not take a single step without the permission of her jailor, namely her guardian. But in her case the term [of imprisonment] is unlimited.
"The Saudi Mahram Law turns the women into prisoners from the day they are born until the day they die. They cannot leave their cells, namely their homes, or the larger prison, namely the state, without signed permission... Although Saudi women are deprived of freedom and dignity more than any other women [in the world], they suffer all these forms of oppression and injustice in bitter silence, [and with an air of] suppressed anger and death-like dejection. Saudi women are peaceful in the full sense of the word, but so far the Saudi state has not appreciated their [noble] souls, their patience, and their quiet resistance..."
"The Clerics, Whom the State Has Authorized to Oppress the Women, Regard Their Silence And Patience As [a Sign of] Mental Backwardness"
"The clerics, whom the state has authorized to oppress the women, regard their silence and patience as [a sign of] mental backwardness and emotional weakness... Thus they have [allowed themselves] to increase the oppression over the decades... They suffocate [the women] in all areas of life by means of oppressive laws [enforced by] the religious police, who follow them everywhere as if they were fugitives from justice. The laws pertaining to women have turned them into objects on which sick men can release their violent and sexual [urges].
"These Saudi clerics deny the Saudi women every opportunity to find a job, get an education, travel, receive medical treatment, or [realize] any [other] right, no matter how trivial, without the permission of their jailor, that is, their guardian - [all] based on oppressive fatwas sanctioned by the male [leaders] of the state."
Our "Mothers and Grandmothers...Enjoyed Much Greater Freedom... Saudi Arabia Has Turned Itself Into the World's Largest Saudi Prison"
"[It is interesting to note that] the mothers and grandmothers [of today's Saudi women] had all these rights, and enjoyed much greater freedom [than today's women] - as did all Muslim women in past eras, such as the wives of the Prophet. [None of these women] were subjected to this oppressive Mahram Law, which is not based on the tenets of Islam and in fact has nothing to do with Islam.
"How blessed is Saudi Arabia, the humane kingdom, which has turned itself into the world's largest women's prison. [This is a land] which permits any man, without preconditions, to take the role of jailor, and which has turned its women into prisoners for life, when they have done nothing to deserve it."
 Mahram, meaning "forbidden," refers to a male relative whom the woman may not legally marry and who can thus serve as her guardian.
 Awan (Kuwait), July 6, 2009. It should be noted that Sheikh 'Abd Al-Muhsin Al-'Obikan, advisor to the king and Shura Council member, recently issued a fatwa permitting women to travel abroad unaccompanied. www.islamonline.net, December 25, 2008.
 http://www.menber-alhewar1.info/news.php?action=view&id=4364, June 24, 2009.