[turtle]

There is more to it. Just an excerpt from the logs:

2013-04-14 04:10:31 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?2013-04-14 04:11:32 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?2013-04-14 04:12:33 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?2013-04-14 04:13:34 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?2013-04-14 04:14:35 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?2013-04-14 04:15:37 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?2013-04-14 04:16:38 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?2013-04-14 04:17:39 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?2013-04-14 04:18:40 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?2013-04-14 04:19:42 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?2013-04-14 04:20:43 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?2013-04-14 04:21:44 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?2013-04-14 04:22:45 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?2013-04-14 04:23:46 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?2013-04-14 04:24:47 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?2013-04-14 04:25:48 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?2013-04-14 04:26:49 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?2013-04-14 04:27:50 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?2013-04-14 04:28:51 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?2013-04-14 04:29:52 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?2013-04-14 04:30:53 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?2013-04-14 04:31:54 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?2013-04-14 04:32:55 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?2013-04-14 04:33:56 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?2013-04-14 04:34:57 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?2013-04-14 04:35:58 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?2013-04-14 04:36:59 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?2013-04-14 04:38:00 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?2013-04-14 04:39:00 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?2013-04-14 04:40:01 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?2013-04-14 04:41:02 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?2013-04-14 04:42:03 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?2013-04-14 04:43:04 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?2013-04-14 04:44:05 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?2013-04-14 04:45:06 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?2013-04-14 04:46:07 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?2013-04-14 04:47:08 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?2013-04-14 04:48:09 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?2013-04-14 04:49:10 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?

This isn't all OptiFine. Also, there was no one online during this time frame either.