I too have noticed that expressing any sort of displeasure about the military is absolutely taboo.
The flag too, but less so.
Other things, in order of decreasing resistance:
– Disliking kids (not that I dislike them, but have friends who don’t care for them and they feel ostracized to even mention it)
– Supporting population growth limits (funny how the thing that could do the most to protect our environment going forward is never mentioned!!)
– Questioning crosses or religious displays on public property
– Thinking the govt bailouts were a good thing