It's really true: those who apply at consulates must follow the instructions on each consulate's website regarding translations, but the jury is out when it comes to getting your documents translated for applying in Italy.
Ultimately, the comune where you choose to apply gets the last word on what to accept and what not to accept, even though Circolare k.28 del 1991 stipulates that translations must be official or "traduzioni ufficiali." As far as "official" is concerned, this can mean one of three things:
1. An American legalization. The translations can be apostilled by a translator located in the U.S. This means the translator will type up a separate statement for each translation in which s/he declares that the translation is a faithful rendering of the original, but s/he cannot attest to the accuracy of any of the statements in the original document. That then gets signed, notarized, apostilled, and attached to the original documents.
2. An Italian legalization in America. The translator can do it old school and go to the local consulate and get a "certificato per traduzione conforme" which is a consular statement declaring that the translation is done well, and at that point basically the consulate takes responsibility for the translations.
3. An Italian legalization in Italy. Your translator, if located in Italy, can go to the local court and do what is called an "asseverazione." It's essentially equivalent to the step in number 1, only it's a sworn statement made in court in Italy as to the accuracy of the translations.
To make the matter even more complicated, some comuni don't care at all and don't want any legalizations, while others will want the translator to simply prepare the statement of accuracy in 1) but not go the entire way and apostille it. To these comuni, an official translation could very well mean just a translation done by a competent translator. So, as you can see, the use of the term "traduzione ufficiale" is not without controversy and is very much so up to interpretation when applying in Italy. Consular applicants have it much easier: the vast majority of consulates will accept just a regular translation stapled to the original without anything further--except for documents such as divorce decrees which for some reason require an apostille. Why? It's Italian bureaucracy--just roll with it!
So the moral of the story is: anyone can do a translation, but it's best to hire a pro because s/he will know what to do if given a specific direction by the comune. It's also best to ask the comune! If you have any questions about translations for applying in Italy, feel free to contact us!