"Judging from the package sent, the perpetrator was clearly trying to silence Ulil by killing him", said Nezar Patria, chairman of AJI (Aliansi Jurnalis Independen / The Alliance of Independent Journalists).
"The case has to be solved. An attack against an advocate of pluralism is a hard blow to our national ideals. Democracy in Indonesia is now in danger".Tempo Interaktif also published the letter that found within the book-bomb's packet addressed to Ulil.
According to Jakarta Globe, there were three book-bombs. The first one addressed to Ulil Abshar Abdalla, co-founder of Jaringan Islam Liberal (Liberal Islamic Network). The second package was addressed to Comr. Gen. Gories Mere, a former key officer of the National Police’s elite counterterrorism unit, Densus 88 (Special Detachment 88). The books sent to Ulil and Gories were titled "They Deserved to Be Killed: Because of Their Sins to Islam and Muslims". The third book-bomb was addressed to Yapto with the titled "Masih Adakah Pancasila?" ("Does Pancasila Still Exist?").
Why Ulil Abshar Abdalla?
Because in 2002 Ulil wrote an article titled "Menyegarkan Kembali Pemahaman Islam (Rejuvenating the Islamic Understanding)" in Kompas, a popular newspaper in Indonesia. By browsing, I also found another piece of story about Ulil published in 2003, just to answer the question of why?
Who is Ulil? Please read at Wikipedia. Now what? Again, a test for the state constitution, Indonesia.