1.   Between abuses of e-mail, some nasty pranks and a careless online gossip columnist, the well-established information anarchy of cyberspace has turned more chaotic and even brutish.

2.   In other cases of noxious fumes that caused no serious injuries, police have suspected copycat crimes or nasty pranks.

3.   Police suspect nasty pranks in some of them.

4.   Scores of people have complained of feeling ill in the subsequent fumes cases, some of which police believe were copycat crimes or nasty pranks.

5.   These have remained unexplained, but copycat crimes or nasty pranks were suspected in some.