and NEVER chmod 777, if something requires write access use 766 or 775
Its recommended to set the robots.txt file to a 777 permission in order for Google Bot to be able to access the file without any complications.
The worst that can happen as a result of using 777 permissions on a folder or even a file, is that if a malicious cracker or entity is able to upload a devious file or modify a current file to execute code, they will have complete control over your blog, including having your database information and password. [source]
