Amid the upheavals in Egypt since January, reports have begun to emerge of a surge in disappearances of Coptic girls.
One priest in Cairo estimates that at least 21 young girls, many as young as 14, have disappeared from his parish alone.
In most cases, when a Christian girl who disappears is found by her family, she has been converted to Islam and married. The Coptic authorities, have even set up a series of refuges in monasteries to handle the growing numbers of girls who wish to return to their families, many of whom are not accepted by their family of origin.
But a worse problem for these women is that their conversion to Islam is irreversible.
Religion is stated on Egyptian ID documents and even though secular law provides for reversions, under the growth of sharia they are very difficult, except for those affording legal advocacy.
This situation is not unique to Egypt. There have been consistent reports of girls being coerced into Islamic conversion and marriage in India, Pakistan, and Sri Lanka.
That many of these girls are initially runaways is not in doubt. However, there is also evidence that a huge number are converted and married against their will.
The situation was documented in a controversial report published in 2009 on conversion and forced marriage of Coptic women by Washington DC-based Christian Solidarity International. The authors are Washington academic Michele Clark and Egyptian Coptic broadcast journalist Nadia Ghaly, based in Melbourne.
Between 2005 and 2008 they interviewed and documented 50 Egyptian women, mostly aged between 14 and 25, who had decided to return to their families. All claim to have been tricked, coerced or raped, converted to Islam and married. Most of the interviewees were trying to reconvert to their Christian identity, with limited or no success. The report's conclusions were printed in several major publications, including Forbes magazine.
Since the so-called Arab Spring, and the ensuing riots at Christian churches, the authors are trying to bring the subject of forced conversion and marriage to greater prominence.
Both groups live extremely closed, highly traditional separate lives and the norms surrounding marriage and sex are almost medieval, says Ghaly.
So, for example, it is not unheard of for a young Christian girl from a poor family to run away from an arranged marriage. Yet a high proportion of these women claim coercion, even rape, despite the shame that such a claim will cause if the girl wishes to return.
Many claim they were kept as virtual slaves. Others who were able to leave could not bring their children. Ghaly claims this is more than overt religious oppression, and amounts to "a form of cultural genocide".
She cites a document published by Human Rights Watch in November 2007, which says that even if Coptic women can obtain a divorce from their Muslim husband, those who wish to return to Christianity "meet with refusal and harassment from the Civil Status Department of the Ministry of Interior".
Under sharia law, reconversion is considered apostasy punishable by death.