Breaking down silos is a frequent organizational mantra. However, if taken to the extreme, you end up with a pile of rubble and scavengers making off with your grain.
The simple truth of the matter is that no organization can be made perfect, they all have their inefficiencies, politics and barriers. Sometimes the more effective approach is to bridge silos rather than break them down. You are much less likely to bring the whole edifice down on your head if you focus on punching strategic holes in the towers and connecting them rather than trying to take on the entire power structure.
Sometimes the silo is more powerful than you. But almost any organizational silo can be pierced by an intrepid orgpreneur.
Build these bridges based on creating results, getting things done, routing around office politics that have things gummed up. You’ll soon be known as the person who gets it done without trying to reinvent the organization first.
C. David Gammel, CAE 
In many situations what is perceived to be a technology-related problem (complaints that IT isn’t run effectively) is really a silo bridging issue. The deployed technology may be fine. The services of IT just aren’t communicated effectively. A solid communications plan for bridging the silos is the foundation of a good technology strategy.
Agreed, Mike.
David, I think you’ve really hit the nail on the head with this post. As does Mike with his comment. I’ve often found that indeed bridging the silos in an organization can bring to light numerous gaps that are actually much easier to fill than you’d think, but because the left hand is effectively communicating with the right the pain point festers, fingers are pointed and the blame often falls on the wrong party. Effective communication solves a great deal!