jurgenhaas/tagadelic — comment on commit 739c096900e8658fe722acff747fbe7b0210d65c
File: tagadelic.module line 240
By jurgenhaas:

$key is an index of an array and to be honest I'm not sure if that could be manipulated in such a way that it could cause harm, can it? If s, you'Re right it should be escaped.