This was received as a comment here - written by Ephraim. I decided to publish it as a blog post, so everyone can read it. If you would like to comment, please only do so if you have something factual to say, I will not be publishing anonymous insulting comments directed at Ephraim.
Dani18.com contains no halacha. The sources are sparse and are aggadic in nature- they are not halachic sources! The basic claim is that this practice is permitted because prophecy remains somehow amongst children and fools. From there, there is an unsubstantiated jump to Facilitated Communication. Can we allow children to gaze into crystal balls, read Tarot Cards and consult the stars because they may be gifted with prophecy? Of couse not! The fact is, that Dani18.com does not in any way provide halachic justification for FC.
Now, the תשורת שי that I mentioned above already prohibits the practice of divining the future by means of a table of letters- even if children are involved. Certainly, that posek was aware that prophecy is found amongst children- and yet he forbade the practice anyway. Why? I suppose it's because of the methodology. Now, it's clear that divination by means of geomancy (throwing soil onto the ground, and then "reading" the random spots produced) falls under the category of קוסם. I doubt it make a difference if we get a child or an autist to throw the soil- it would still be forbidden. (Indeed, even Moshe Rabbeinu would be forbidden to perform divination! It's not about who is doing it- it's about what is being done.) Similarly, the Malbim understood the ouija board as included in the prohibition of קוסם. He did not exclude children from the prohibition.
Dani18.com does cite R' Eliyahu Dessler, but actually distorts his message. Rav Dessler differentiates between the premonitions of a kosem (what he calls "telepaths") and a true prophet. He cites the Rambam who explains that suppressing the intellect to awaken imagination (what we would refer to as a trance state or the like) is a definition of קוסם. Rav Dessler writes that this is a inferior process to that of a true prophet.
What does Rav Dessler actually write concerning children and prophecy? He writes about them in the context of discussing forbidden divination! He writes:
זהו ענין הקוסם שהיה יכול לפעמים להגיד עתידות...ואולי מענין זה הוא מה שאמרו ז"ל (בבא בתרא יב:)"מיום שחרב בית המקדש ...ניתנה נבואה לשוטים ולתינוקות
Rough translation: "...this is the concept of forbidden divination in which a person can occasionally foretell the future.. and perhaps this is the same idea that Chazal spoke about that "From the day that the Beis HaMikdash was destroyed, prophecy was given to fools and children".
It's very clear that Rav Dessler holds that the prophecy of children and fools is in the same inferior category as a diviner.
Now, we must distinguish between FC in it's secular and spiritual forms. This is vital halachically. The secular claims of FC proponents have been disproven. It works for a few exceptional individuals, and generally speaking it has failed. Furthermore, it makes no sense scientifically. Why? Because even higher functioning autists who do speak, communicate in an idiosyncratic manner. That's part of the definition of autism. Yet, we don't see idiosyncrasies in FC messages. That would indicate that FC is not coming from the children. In summation, FC doesn't make sense and has been proven ineffective. Practices that don't make sense scientifically and also have been proven ineffective are prohibited as דרכי האמורי. This is the opinion of the overwhelming majority of poskim!
Now, the spiritual proponents of FC now step in with an even more astonishing claim. True, the messages of FC can't be explained scientifically. They agree that the messages don't contain the expected idiosyncrasies. But instead of admitting that FC is phoney, they claim that the lack of idiosyncrasies proves that the messages come directly from the soul! After all, it's been proven scientifically that it can't come from the mind of the child- so it must come from the soul. Once they make this claim, FC moves from the category of דרכי האמורי into the category of קוסם. Why? Because קוסם does not include any scientific form of prediction. Consulting a meteorologist is not forbidden, since the predictions are scientific. Only non-natural methods of prediction are forbidden. The only exceptions are the גורל הגר"א (and its equivalents) and asking a child to cite a posuk. (Think about this: why is allowed to ask a child to cite a posuk? Why is it not also permitted to ask a child to cite next weeks lotto numbers? Why davka a posuk?)
Nothing I wrote is opinon- it's all clear halacha. The halacha is clear for those who bother to learn it. Check out the Sefer HaMitzvos of the Rambam and see his definition of קסם. Also look at the entry for Kosem at http://www.aspaklaria.info.