A lot of sites have forgotten to protect their SVN. It’s easy to check if your site is open for grabs,  just see if you can access  http://YOURSITE/.svn/entries

To protect your site, add the following to your .htaccess file:

<ifmodule mod_rewrite.c>
RewriteRule ^(.*/)?.svn/ - [F,L]
ErrorDocument 403 "Access Forbidden"
</ifmodule>