What does Israel fear from media coverage?

The New York Times, today:

A day after Israeli commandoes raided an aid flotilla seeking to breach the blockade of Gaza, Israel held hundreds of activists seized aboard the convoy on Tuesday . . . .Reuters reported that Israel was holding hundreds of activists incommunicado in and around the port city of Ashdod, refusing to permit journalists access to witnesses who might contradict Israel's version of events.

Physically blocking journalists from reporting on their conduct is...