Webproxy log help me

IP address or MAC address does web proxy logs.
What do you suggest.
Best Regards.

webproxy log output:

May/13/2013 21:28:25 web-proxy,debug X-Proxy-ID: 876680281
May/13/2013 21:28:25 web-proxy,debug X-Forwarded-For: 173.237.187.170
May/13/2013 21:28:25 web-proxy,debug Via: 1.1 179.13.14.15 (Mikrotik HttpProxy)
May/13/2013 21:28:25 web-proxy,debug
May/13/2013 21:28:25 web-proxy,account 178.150.51.131 GET http://www.google.com/search?as_q=Asacol+cod+nextday+cod+buy++"Thread-"&num=100&hl=en&output=ie&filter=0 action=allow cache=MISS
May/13/2013 21:28:25 web-proxy,debug GET /search?as_q=Asacol+cod+nextday+cod+buy++%22Thread%2D%22&num=100&hl=en&output=ie&filter=0 HTTP/1.1
May/13/2013 21:28:25 web-proxy,debug Accept: /, text/html, application/xhtml+xml
May/13/2013 21:28:25 web-proxy,debug User-Agent: Mozilla/4.0 (compatible; MSIE 4.01; Digital AlphaServer 1000A 4/233; Windows NT; Powered By 64-Bit Alpha Processor)
May/13/2013 21:28:25 web-proxy,debug Referer: http://www.google.com/search?as_q=Asacol+cod+nextday+cod+buy++"Thread-"&num=100&hl=en&output=ie&filter=0
May/13/2013 21:28:25 web-proxy,debug Accept-Language: ru-RU,ru;q=0.8,en-US;q=0.6,en;q=0.4
May/13/2013 21:28:25 web-proxy,debug Accept-Charset: windows-1251,utf-8;q=0.7,*;q=0.3
May/13/2013 21:28:25 web-proxy,debug Host: www.google.com
May/13/2013 21:28:25 web-proxy,debug Pragma: no-cache
May/13/2013 21:28:25 web-proxy,debug Cookie:
May/13/2013 21:28:25 web-proxy,debug X-Proxy-ID: 876680281
May/13/2013 21:28:25 web-proxy,debug X-Forwarded-For: 178.150.51.131
May/13/2013 21:28:25 web-proxy,debug Via: 1.1 179.13.14.15 (Mikrotik HttpProxy)