Spamming bots

[GoogleCodeExporter]

How to avoid spam bots that places text in search field and text is stored in 
last search keyword module and also somewhere in website as separate page.
Obvious cleaning cache doesn't help and bots comes many times daily..and spam a 
lot. 

Sample spam text: "thanks for a great  web log pwmjfuzvfn click here 3 nojyyzvo 
o sryzdujasi urlhttpwwwrfnibbnrjlbineto" 

Original issue reported on code.google.com by [email protected] on 3 Jul 2013 at 9:06