Found some consecutive requests from Baidu crawler IPs with odd user agents for the requests for that range.
Checking for mobile pages?
123.125.71.98,China,"Mozilla/5.0 (Linux;u;Android 2.3.7;zh-cn;) AppleWebKit/533.1 (KHTML,like Gecko) Version/4.0 Mobile Safari/533.1 (compatible; +http://www.baidu.com/search/spider.html)",/index.html
No clue, FF asking for robots.txt?
180.76.5.93,China,"Mozilla/5.0 (Windows NT 5.1; rv:6.0.2) Gecko/20100101 Firefox/6.0.2",/robots.txt
180.76.5.89,China,"Mozilla/5.0 (Windows NT 5.1; rv:6.0.2) Gecko/20100101 Firefox/6.0.2",/robots.txt
180.76.5.87,China,"Mozilla/5.0 (Windows NT 5.1; rv:6.0.2) Gecko/20100101 Firefox/6.0.2",/robots.txt
At first I was thinking screen shots, but robots.txt?