All - apistatus.twitter.com is monitoring API latency. However the reflection of latency in the green check marks is currently not quite what you might expect. The green only turns to yellow if latency is below performance thresholds for the entire day. We're working with our vendor on making this a reflection of current performance vs. the entire day's performance. Until then, you can always click on a specific monitor and see a graph of latency. Sorry for the inconvenience, we'll let you know when it's fixed.
---Mark http://twitter.com/mccv