问题 I have been using the LinkedIn API without trouble for a while and suddenly today calls that used to work started failing. The API returns an HTML page titled "999: request failed". The body of the page says "Sorry, we are unable to serve your request at this time due to unusual traffic from your network connection." What does LinkedIn mean by "unusual activity"? Has LinkedIn implemented limits to the number of calls my application can make in a day? If so, what are they? Or, are they