What flag will people mistakenly go after next? Maybe the Gadsden Flag?

I hope not. The Gadsden Flag was a favorite of mine, even before it was co-opted by the Tea Party.
Personally, I think that these little "contraversies" only serve as distractions from real issues. I can think of a hundred things more pressing than Confederate Battle Flags.
We are so busy talking about and being "outraged!" by things that don't matter that important issues go by the wayside or are addressed unnoticed.
I think that there are those who benefit from that, and we are playing into their hands.

I jokingly made the remark that PETA will go after this flag; because it promotes the stepping on of snakes. This knee jerk reactionary liberalism needs to stop before Doctor Suess Books are next on the "offensive" materials list. Come on people we need to wake up and smell the coffee; or is that offensive too?

They could. After all the narrative is much more important than reality in these cases. They're doing their best to erase America's history and culture so this flag might really be next. However, I woudl bet money this entire flag and statue show down has been to set the stage to remove the American Flag. Although if you think about it while the Rebel Flag has caused a stir removing the Gadsgeen and especially the American Flag will provoke attack and real protest.