The advantage is firmly in the hands of the attackers right now. The number of easy to use tools available and the speed that new vulnerabilities are incorporated into these tools greatly outpaces the speed that most organizations can stay on top of the threats. No matter how many precautions you have taken, a breach will occur. Although there are many things you can do to minimize the risk of a breach, you should operate under the assumed breach mentality — you have already been breached, you might just not know it. What are you going to do now?
Data centers are particularly juicy targets for attackers because there are so many different systems consolidated in a single place. This makes it easy for attackers to pivot from a breach of one system to another. Fortunately, the physical security of data centers is usually much better than a standard corporate network. Unfortunately, when you evaluate the digital security of data centers, we are far behind. We need to do a better job of recognizing the difference between how to secure the digital environment from the physical.