A nice post at NPR showing how contagious Ebola is compared to other viruses:
On average for the most contagious outbreak, one infected Ebola patient will infect 2 additional people. That is still pretty high, but that doesn't mean one sick person will infect a subway full of people. If infected people are identified before they become contagious, then it is pretty easy to nip in the bud.
Remember folks: your hands are dirty, dirty things that are constantly sampling your environment. Stop touching your face! And wash those suckers.