No these attack are incredibly rare and even if you told me there will be an attack on movie theater tomorrow consider this: There are about 39,000 theaters in the US ,if one where to be attacked at random, the odds of you being in the one attacked in my hypothetical scenario is .00002; that number comes out of my calculator in scientific notation, and note that is just you being in the theater , an attack will only happen at once showing time of multiple, so the odds of you being there at the time of the attack is even lower and... you get the picture I have much more probable things to worry about.