In response to the report of a minor bug it appears HTML support has been disabled which is pretty heavy handed.
Gawd, I've managed to leave this a full month without replying. Went away to check something and then got stuck into other work and forgot to come back. *ahem*
Anyway: responding to this specifically, when we tested the "minor bug" internally it turned out to be a more of a "critical defect" situation. We've added some protection to prevent the immediate issue resurfacing, however we do need to keep some restrictions in place in order to ensure security of the platform.