Because it "receives orders from the American administration." "Al-Qaida threatens to topple Lebanon govt.," from [1] AP:

BEIRUT, Lebanon - Al-Qaida has purportedly issued a statement threatening to topple Lebanon's "corrupt" Western-backed government, according to a London-based Arabic newspaper Monday.

The Al-Hayat newspaper reported that al-Qaida issued the statement from the Palestinian refugee camp of Nahr el-Bared in northern Lebanon.

"The organization has arrived in Lebanon and we will work on destroying this corrupt government that receives orders from the American administration," Al-Hayat said, quoting the statement.

The Lebanese government is denying that this statement really came from the A-Q boys. But of course, the Lebanese government is in denial about a lot of things.