Capacity planning is important for the big names, too

It probably doesn't happen that often, but even the big names in our industry can run out of steam sometimes. A recent example from Twitter, which ran over capacity in the morning U.S. time few days ago. Here's a screenshot of how it looked like:

Yes, such an error message can be considered bad, but in this case, it was well managed. Something to remember even if you are developing sites for a smaller audience; the ASP.NET Yellow Screen of Death for instance or the basic IIS message probably isn't best PR possible.