There is an unfortunate myth that a datacenter is less secure than a company keeping their servers in house. This keeps smaller, but high website traffic businesses from utilizing the benefit of colocation at a datacenter. Generally speaking, the average datacenter is a far more secure place for a business to house their server; the physical protection alone is better than mot companies could dream of having. The servers just don’t sit out in the open either, they are locked in cages.
As to the Internet security services which a datacenter offers, the intrusion detection and prevention monitors should always detect and report any intrusion attempts both inside and outside the network. These detection services are also kept constantly up-to-date, a chore few in house IT departments have time to do on a consistent basis.
A recent security breach at Texas data centers operated by a large payment processor, the biggest breach involving payment card data, compromised more than 100 million credit and debit cards. This breach effected myself and I can personally state that having ones debit and credit cards unceremoniously canceled is a major headache.
However, this company could have avoided the multiple class action lawsuits being filed against them by utilizing an outside datacenter with state-of-the-art Internet security. Companies who outsource their IT needs to a datacenter instead of running their own will typically have much better security if they chose the center wisely.