<human>: "Hit 'Em Up" is a diss song by rap artist 2Pac featuring his group the Outlawz. It is the B-side to the single "How Do U Want It", released on June 4, 1996. The song's lyrics contain vicious insults to several East Coast rappers, chief among them, Shakur's former friend turned rival, The Notorious B.I.G., also known as Biggie Smalls.

Finishing the recording of the song, Shakur felt very positively about the track, saying the "song is going to be playing in every club., every country. Deejays are calling from everywhere, wanting to get a piece of this." "Hit 'Em Up" appeared first as a B-side, on the single "How Do U Want It", by Shakur featuring The Outlawz. On June 4, 1996 under the label Death Row Records, "Hit 'Em Up" was released on compact disc, 12-inch, and a 45 RPM. The original cover for the single had Puffy's head on a snake's body, and Biggie's head on a pig's. It also appeared posthumously on several compilations, including the 2004 release of Shakur's last recorded live performance, Live at the House of Blues. "Hit 'Em Up" was also remixed on Nu-Mixx Klazzics. Upon its release, "Hit 'Em Up" received frequent radio airplay, which was attributed to the public interest in the ongoing feud and radio stations' desire to garner high ratings. However, some radio stations, such as the Los Angeles-based KPWR, refused to play it. The follow-up to "Hit 'Em Up" was the song "Bomb First (My Second Reply)".  "Hit 'Em Up" has been called "controversial," "infamous," "disturbing," and "brutal." Shakur's insults against virtually the entire East Coast scene of rappers were said to be ferocious. The song, along with "Dear Mama," has been viewed as one of Shakur's songs that resonated with and was spoken of the most by young people. Some felt that "Hit 'Em Up" showcased Shakur ranting and raving like a fool, and J.R. Reynolds of Billboard called it horrendous, noting that Shakur revealed his true colors upon recording the song. He also went on to say that although sympathetic to the shooting, "Hit 'Em Up" had "fan[ned] the flames of hatred ...and affect[ed] an entire black culture's psyche"; he called the song "repugnant and unacceptable." Among associates of Shakur, it was called a "bad-luck song." Los Angeles radio director Bruce St. James called the song "the be-all, end-all, curse-word, dirty-lyric, violent song of all time." Game's manager has called it the best diss record. Documentary filmmaker Carl Weston believed that "most people in Biggie's shoes would have wanted to at least hurt Tupac" in a Spin magazine interview.  Among musicians, the song drew criticism from singer Dionne Warwick, and disapproval from fellow rappers Kool Moe Dee and Chuck D, as written in their book There's a God on the Mic: The True 50 Greatest MCs. They felt that although Shakur was one of the most substantive rappers of that period, he had gone too far with "Hit 'Em Up," causing some of Shakur's fans to turn on him, according to the two rappers. CANNOTANSWER

Using a quote from the above article, answer the following question: Why did they refuse to play it?
<bot>: )".  "Hit 'Em Up" has been called "controversial," "