I mentioned this idea recently offhand in a previous post ( How did the חרטומים turn blood into water?) and I bleive that it bears repeating.
The gemara in Shabbos comments that כפה עליהם הר כגיגת by Matan Torah. The obvious question is didn't they say נעשה ונשמע, meaning that they excepted the Torah willingly? The Meshech Chochma answers that the gemara is meant to be taken allegorically. The revelation when Bnei Yisrael left Egypt, krias yam suf, and matan torah was so great that it was as if Hashem forced them to accept the Torah. The revelation was so great that they could not say no, Hashem's presence in the world and Torah's importance were self understood like the sun is shining. They understood that if they did not accept the Torah the world would be destroyed, not as a threat but as a fact, as reality. In other words, their free choice was taken away by the tremendous revelation.