Tweeting to me is connecting with people and finding out the latest information going on in the world. People and companies might have different uses which is their business but when something like yesterday's bombing at the Boston Marathon happens it should be a flag up that you need to either rethink you social media plans or build in an emergency tweet stop. It was annoying to say the least when trying to get information on a friend running the marathon that all these scheduled tweets kept showing up in my feed. My annoyance is not the point though... your branding is.
Gary Vaynerchuk summed it up best:
If you must use someone else to tweet or use an auto program (which you totally don't have to!) make sure you have plan when a national tragedy is striking. Out of respect, out of decency, and selfishly out of your own branding value: don't tweet when others are looking for news, mourning, or trying to really connect- otherwise you look like an ass.
Attention TweetDeck: My suggestion is to have an auto-stop on scheduled tweets in times of national crisis. This can be an option that is chosen at set-up and sends a notification to user that their tweets have been stopped due to X-reason which can be restarted easily. Or a second option is a notification that gives them a heads-up there is a national tragedy/disaster and that they have option to reschedule all tweets to resume X-hours later. I believe this would be a highly useful and appreciated option for your users.