Well, of course Lady Gaga is also known in Europe. But this does not directly mean that the trademark Lady Gaga is a reputed trademark. This should be demonstrated in a dispute by the means of extensive evidence.
In a recent opposition proceedings with the OHIM, this went wrong for Lady Gaga. She had filed an opposition against the trademark Gaga. The opposition was filed on the basis of the risk of confusion and freeriding on / dilution of a famous trademark. After the specification of this trademark application was limited by the applicant, the last ground remained. Lady Gaga filed some prints from Wikipedia and some other prints of her appearance in the media. Well, the OHIM was far from impressed. Wikipedia is not seen as an objective source and the rest of the evidence was not convincing.
With the internet as source, it is rather remarkable that the Opponent filed so little evidence. Not very Lady Gaga-like.
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