Whiterun and having vampires attacking my friends on the other side of town (even after the main quest they attack just as much). I explored that area of the city several (ingame) days later only to find ash piles and dead npcs. Wtf? At least with a dragon you ALWAYS know it's happening and they tend to focus on you, but this is getting rediculous......Note that this is NOT a problem for everyone, some people rarely seeing vampires attack at all, but many people find it difficult to focus on anything BUT this dlc when random encounters like these distract from everything else. Regardless, this leaves many players in an endless war of attrition, where towns will EVENTUALLY be left as ghost towns. This could have been resolved in several ways:
1. Make it so that instead of repetitive and mindless vampire killing, you can help the guards FIGHT BACK by training and upgrading them. If you're a vampire hunter, doesn't this make sense? This will decrease the liklihood of attack, make attacks happen outside of the gates with vampires TRYING to get in, and increases guard's chances of killing them quickly should they break in. If this is an "invasion of vampires" they should have gone all the way and let people REALLY fight back.
2. Make defenseless npcs run instead of fight using the system that worked in Oblivion, where every character has a level of courage and aggression that determines whether they fight or run. This is absent in skyrim apperently.
3. Make it so that, instead of making characters essential, important npcs can only be killed by the player, sparing them from dragons and vampires. Fallout New Vegas worked fine with no essentials. Skyrim needs SOME system however, because of all the random attacks on citizens. OR they could have made generic npcs be replaced by new ones. It doesn't make sense that no one ever moves back into houses or works at inns or shops after the previous owner dies.
But none of this was done. Bethesda really didn't think this aspect through. The beta testers allegedly complained about this, thinking it was a bug, but bethesda left this in.