I have just upgraded to 4.3 and during browsing of my new settings I found that I can't disable pattern screen lock because it "turned off by administrator, encryption policy or credential storage". I consider this as the limitation of my freedom of using the device. After searching the Internet I have found that this is probably due to some certificates installed on the device that require this level of security and it can't be prevented by using "Clear credentials" from security menu in Settings. However I don't really want to clear ALL the certificates. I'd rather remove only the certificates that require this level of security. Thanks.

The firmware is 4.3 (official).

By the way I will use pattern unlock as I did before. The problem is I don't like some idiotic certificate providers to mess with my device.