Found in my error-list ...

[DSF]

This line have I found in my Server-Error-List.
What's this?
Hacking?

[Fri Oct 05 13:59:59 2012] [error] [client 208.53.158.59] File does not exist: /var/www/host/MYDOMAIN.TLD/httpdocs/+++++++++++++++++++++++++++++++++++++++++++++++++++++Result:+chosen+nickname+"Quianacpv4";+registered;+logged+in;+no+post+sending+forms+are+found;+probably,+registration+failed+(activation+code+was+sent+, referer: http://www.MYDOMAIN.TLD/+++++++++++++++++++++++++++++++++++++++++++++++++++++Result:+chosen+nickname+%22Quianacpv4%22;+registered;+logged+in;+no+post+sending+forms+are+found;+probably,+registration+failed+%28activation+code+was+sent+/+there+are+additional+protection+used+on+forum+/+forum+SQL-error+/+...%29;

 

[DSF]

Nobody has an idea?

 

[Jake Bunce]

Clearly that's a stupid request that does not exist which is what that error is telling you. I don't recognize the URI. It's probably a random request submitted by a bot.