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 https://YOURSITE/.svn/entries
To protect your site, add the following to your .htaccess file:
[sourcecode language='html']
RewriteRule ^(.*/)?.svn/ - [F,L]
ErrorDocument 403 "Access Forbidden"
[/sourcecode]