Yes, it is a major concern. My Brother is the ISP for ECN and a number of other websites. Many of these websites are 'e-tailers' meaning they do business selling things on the web.
Many thousands of $$ get lost every day that the lines are down, but what can be done about it? Most of the lines are overhead and in some sparsely populated areas. I don't think there's any doubt that someone has an ax to grind, possibly against the Telco company and that's why this is happening.
Several years ago when the servers were set up at this location they had looked into getting a Cable connection (I don't know too much about this, so am unsure of terminology) and were quoted a price of $50,000 just to bring the line to the building. That might start looking like a bargain if this stuff continues.