But the security argument itself raises questions. First of all, you now have to ask what is out of bounds as far as maintaining security. What freedoms must we give up in order to be secure? The two concepts are at odds by their nature, and making a security argument for suspending any one freedom starts you down a slippery slope.Also, whether the burqa demeans women is not relevant, because to the best of my understanding the reason for the ban is security. The theoretical demeaning of women is a theological issue, but the government, and socieities in general aren't concerned with theological dilemmas, they're concerned with social dilemmas. A government doesn't have an issue with Biblical extremists because they take the Bible literally, it's because (some of them) intend to burn down mosques and the like, which is a social/security issue.
The other question is, why just burqas? What about baggy pants? You can hide weapons in baggy pants, and also it's really easy to trip and fall if you're wearing baggy pants. Ultimately, both strike me as cases of profiling, more than anything. And profiling is frankly unproductive, even from a security standpoint. You won't be able to single out a security threat based on what a person looks like, or even technically what they wear. It's actions that define security threats, and being able to identify and act on those actions is infinitely more important than simply quashing out some arbitrary quality based on profiling.