First off read this article - it's seems like the best one to explain the why. There are more articles here, and here.
Basically, the two Icelandic producers of a 2007 hit movie in their country called Astropia claim that Heroes ripped off their storyline in the episode 3.19 "Shades of Gray."
The storyline in question is the one where Claire goes to get a job in Sam's Comic store. In the movie, a girl who's had it all finds herself in need of a job and decides to work in a comic book store. That's the only similarity I see in it, but the articles are saying the producers are trying to file an injunction.
What does that mean and do you think it's worth it? After all, looking at the bigger picture, the overall storylines are quite different, though that aspect may be similar.
