The source is this tiny headline in Hebrew: Walla, 2 Al-Jazeera reporters arrested after entering a closed military perimeter
From what I heard, Al-Jazeera has been circumventing Israel's censor rules and have been reporting exact rocket hit locations, which tells their Hammas counterparts how well their aim was.
Could be a big nothing, though I'm wondering why this channel is even allowed to broadcast from Israel considering that they held a massive party to a child murdering terrorist in Lebanon after he was released from Israel. They have been shown to support terrorists time and time again and to incite hatred, racism and extremism in the Arab world. What's the point of allowing them a foot hold in Israel? (Except to spy on them, and their terrorist operators in Gaza, Iran and Qatar - OK, there's a reason)
For a video of Al Jazeera's well known depravity, click here:
Little green footballs:LA Times Writer Praises JihadTV
Update: Another version, now in English: IDF detains 2 foreign reporters for entering restricted military zone (ynetnews)
Two Al-Jazeera reporters with British passports were detained by IDF soldiers after entering a restricted military zone near the Kisufim checkpoint. They were taken in for questioning by police