eWeek reports that The Knack is suing Yahoo, Amazon, Apple, Napster and RealNetworks for distributing copies of Run DMC’s It’s Tricky. The song samples The Knack’s My Sharona. Although Run DMC’s song dates from 1986, The Knack argue that they only found out about the song in 2005.The IPKat doesn’t think that such actions should be encouraged. How sensibly can online music services provide operate if they are at risk of actions from way back when?