The Fine Print: I am not an employee of Exodus Communications, though my previous employer is a customer. This writeup is not intended to be a solicitation or recommendation.

Saying that Exodus Communications is "a colo company {with} a bunch of data centers" (and they have several outside of the USA now) is a bit of an oversimplification. If you have data worth protecting, or a web site that can't afford to go down for more than two minutes, and if you have the cash, Exodus is as good as any colocation outfit out there. In some ways (most notably physical security), it's better than most.

A typical Exodus facility is a heavily-modified warehouse in an industrial park that's not too close to a dense population center. The warehouse is reinforced to meet current California earthquake resistance code, even in Waltham, MA and Sterling, VA, where a tractor-trailer convoy can cause a bigger hit on the Richter Scale than a slipping fault line. A concrete overhang over the door prevents anything taller than 7.5 feet from approaching, and concrete pillars and a curb extension make it difficult for a kamikaze vehicle to get even that close. There are no plate glass windows, and vehicles are not permitted inside the loading dock -- any bulky equipment (that won't fit through the front door) has to be hauled in on hand trucks.

Inside, a security guard sits inside a bulletproof enclosure. Offices for the Exodus staff are behind a fire door which leads to a section isolated from the data centers. The fire door leading to the data centers actually opens on an airlock-type structure: the doors at both ends of the short hallway cannot both be opened at once.

The data center itself is climate controlled with conditioned power and multiple fire detection systems. Your typical cage has a standard key lock, but if you're really paranoid, you can buy yourself a fully-enclosed mini data center of your own, with its own independent power and ventilation, and a biometric lock.

A typical facility has multiple fiber lines leading out to the Internet, each to a different ISP, and the lines themselves are spaced out around the building.

The one complaint I would have is that the human guards, being in a place where nothing happens, came off as being a smidge on the lax side, at least on the times I've visited my company's cage.

Yes,, home of Slashdot, uses their services. So does eBay and a number of financial services companies.