Tensions online can heat up between dedicated, hardcore fans of each respective fandom. (I think of the traditional feud between D.C./Marvel comics, which now extend to the movies.) But that's it, just angry words.

Except this time, things got out of hand between STAR WARS and DOCTOR WHO fans...

http://www.bleedingcool.com/2013/05/15/star-wars-vs-doctor-who-now-it-gets-violent/