"USA, you will pay!" chanted more than 100 participants in a pro-bin Laden protest outside the U.S. Embassy in London on Friday.Al-Qaida's plots are usually large-scale and involve planning over months or even years. But Western intelligence officials say they are seeing increased chatter about cheap, small-scale attacks -- perhaps by individuals or small extremist groups inspired to take revenge for the killing."The blood of the holy warrior sheik, Osama bin Laden, God bless him, is too precious to us and to all Muslims to go in vain," the statement said. "We will remain, God willing, a curse chasing the Americans and their agents, following them outside and inside their countries.""Soon, God willing, their happiness will turn to sadness," it said, "their blood will be mingled with their tears.The al-Qaida statement, entitled "You lived as a good man, you died as a martyr," did not name a successor to bin Laden. His deputy, Ayman al-Zawahri, is now the most prominent figure in the group and a likely contender to take his place."The soldiers of Islam will continue in groups and united, plotting and planning without getting bored, tired, with determination, without giving up until striking a blow," the statement said.It said bin Laden was killed "along an established path followed by the best of those who came before him and those who will come after him."The acknowledgment by al-Qaida should remove doubt among all but the most die-hard conspiracy theorists that bin Laden is in fact dead.