tedster - 3:44 pm on Sep 17, 2012 (gmt 0)

Here's my thinking. If traffic shuts off at roughly the same time every day, that's one scenario - and it could possibly be an effect of mano factors. But if traffic stops after a certain LEVEL is reached, that's a very different scenario and strongly does suggest intentional throttling.

It doesn't 100% prove throttling, no - but it does look highly suggestive if the traffic stops at a certain level no matter what time of day that level is reached.