The icon - as Combuster already noted on the talk page - is labeled Public Domain by its author, so it's safe to re-use here.
The template is quite obviously a verbatim copy from Wikipedia, i.e. text under the GFDL (or whatever the acronym for the GNU documentation license is). That alone would be enough to have second thoughts about an inclusion. The clearer point against that edit however, is that it is
Italian ("avviso-testo"). Nothing against Italians or their language, but our Wiki is English...
What is the policy? If a copyright infringement is perceived, I'd say revert first, talk later, as it could result in
legal troubles. The revert could be reverted any time if we get to agree that inclusion is OK (as with the icon).