Some more thoughts from Moslems on the issue...
5. Hijaab prevents molestation
The reason why Hijaab is prescribed for women is mentioned in the Quran in the following verses of Surah Al-Ahzab:
"O Prophet! Tell thy wives and daughters, and the believing women that they should cast their outer garments over their persons (when abroad); that is most convenient, that they should be known (as such) and not molested. And Allah is Oft-Forgiving, Most Merciful."
[Al-Quran 33:59]
The Quran says that Hijaab has been prescribed for the women so that they are recognized as modest women and this will also prevent them from being molested.
http://www.irf.net/irf/dtp/dawah_tech/mcqnm3.htm
Further, they directly attribute 'rape' to the lack of modest dress...
"11. USA has one of the highest rates of rape: United States of America is supposed to be one of the most advanced countries of the world. It also has one of the highest rates of rape in any country in the world. According to a FBI report, in the year 1990, every day on an average 1756 cases of rape were committed in USA alone. Later another report said that on an average everyday, 1900 cases of rapes are committed in USA. The year was not mentioned. May be it was 1992 or 1993. May be the Americans got bolder in the following years. Consider a scenario where the Islamic hijab is followed in America. Whenever a man looks at a woman and any brazen or unashamed thought comes to his mind, he lowers his gaze. Every woman wears the Islamic hijab, that is the complete body is covered except the face and the hands upto the wrist. After this, if any man commits rape he is given capital punishment. I ask you, in such a scenario, will the rate of rape in America increase, will it remain the same, or will it decrease?"
(Ibid).
Note, also this info can be found at
http://www.islamicvoice.com/august.2002/religion.htm
In a society which shamelessly publicly exposes a woman's body and intimate requirements where nudity somehow symbolizes the expression of a woman's freedom and where the most lustful desires of men are fulfilled unchecked - it is little wonder such an introspection leads many Muslim women to the decision to wear hijab.
http://www.worldofislam.netfirms.com/hijab.html
In response to lust and desire, men look (with desire) at other women while they do not mind that other men do the same to their wives or daughters. The mixing of sexes and absence of hijab destroys the Gheera in men. Islam considers Gheerah an integral part of faith. The dignity of the wife or daughter or any other Muslim woman must be highly respected and defended.
http://www.islamworld.net/hijabvirtue.html
Where promiscuity runs rampant, Islam builds a society where children know their fathers, and fathers are responsible for their wives and children. By severing the loose ties of lust, Islam restores the lasting ties of partnership. Where the sexual society objectifies, Islam humanizes.
http://www.geocities.com/Athens/Parthenon/4482/article6.html
Note; it is to help people with their lusts. And as it's women who need be covered up more so than men (and it's applied more to women), it's because men can't control their lusts.