Recently a client of mine got a call by an irritated competitor (he's one of the persons who has good relationships with everyone, so that’s no surprise).
She complained that he was using her brand in his ads. As I was running all his ads and I would never do that (usually you also can't) I immediately had the answer of course: Keyword insertion.
The screenshot I saw confirmed that: her brand name was writing wrongly (the second word started lower case).
But now try to explain that to the competitor. They are small businesses and might not even have their brand name registered so that they can disallow using it in ads.