21.   Undercover purchases are a common tactic of drug agents, but appeals courts have reversed convictions gained by firearms agents posing as felons buying guns.

22.   Wiretapping to gather compromising material on political opponents is a common tactic in Ukraine, Russia and other former Soviet republics.

23.   A common Israeli tactic is to send the army into a Palestinian town and round up hundreds or even thousands of Palestinian men for questioning.

24.   A common tactic was for whalers to trap infants in nets to attract the mother, then slaughter them both.

25.   A general strike is a common tactic the political parties use against the government.

26.   A general strike is a common tactic used by political parties against the government.

27.   Car bombings using booby-trapped car have become an increasingly common tactic of extremists.

28.   Greenpeace recently tried to halt BP operations in North Atlantic by illegally occupying offshore oil equipment, a common tactic for the group.

29.   He said planting drugs on people is a common tactic in Russia to extort money or get information.

30.   He said there was no indication of the existence of a trend in wire-tapping, although it had been known as a common tactic in industrial espionage among businesses.