Because fopen return the resource handle of the file it opened not the contents.
Because fopen() returns a resource pointer to the file, not the content of the file. It simply opens it for subsequent reading and/or writing, dependent on the mode in which you opened the file.
You need to fread() the data from the resource referenced in $handle.
This is all basic stuff that you could have read for yourself on the manual pages of php.net
Use
<?php
$data = file_get_contents("https://graph.facebook.com/search?q=mark&type=user&access_token=2227470867|2.mLWDqcUsekDYZ_FQQXYnHw__.3600.1279803600-100001317997096|YxS1eGhjx2rpNYLNE9wLrfb5hMc.", "r");
echo $data;
?>
Once you have created your $handle you now need to fread() the contents.
$contents = '';
while (!feof($handle))
{
$contents .= fread($handle, 8192);
}
fclose($handle);
echo $contents;
source: php.net/manual/en/function.fread.php