Metallica (the band) and LG (the electronics giant) recently were involved in an opposition procedure before the EUIPO. LG had filed the trademark Metalica for, among other, telephones and watches. The musicians were not very happy with this and immediately filed an opposition.
The first question that the EUIPO had to deal with is whether the METALLICA trademark had been genuinely used in the past 5 years. Often a difficult issue for the trademark owner, for instance it is already very time-consuming to gather all the evidence. Especially with bands, the question is whether a name is actually used as a trademark for example clothing or that the bandname on the t-shirt is just a reference to the band name (and not a clothing brand in itself).
The proof of use filed by Metallica shows several bracelets and the like which are for sale through the Metallica webshop. This at least evidences the use for the products in question. The evidence is weighted by the EUIPO on the time, place, scope and nature of use. The EUIPO concludes that the evidence is not very extensive or very convincing, but just enough to show that the trademark was in use for jewellery (as a distinguishing sign, thus a trademark).
Since the trademarks are very similar, the follow-up assessment is a piece of cake for Metallica: the opposition is upheld in its entirety.