Unable to Block LinkedIn Chat Uploads using Application Classification.
Using Application Operations block LinkedIn Messaging Uploads.
1) Make sure ProxySG is licensed for "Application Classification" & it is Enabled as in below screenshot.
2) You need to make sure "SSL Interception" is enabled on ProxySG
3) Create a Web Access Layer rule with "Destination: Combined Destination Object"
On Top box, select "Application Name" and select "LinkedIn" as Application as below
On Bottom box, select "Application Operation" and select all "Uploads" as below
4) You can limit rule with specific "source objects" or "Any" with meaningful Destination object name & Action as "Content Filter Deny"
Important Note: Blocking downloads has no control for social networking sites. Downloads from social networking is too generic (you can't block download from anyone's post), Downloads is more appropriate for categories like file storage and emails. Below are some of possible operations possible using "Applications" & corresponding "Application Operations". You can review it under "sitereview.bluecoat.com" > Application > Application Descriptions > LinkedIn