From the information given, what seems to be the main flaw in each of the following statistical generalisations?

(i) Banking industry employees are facing a crisis, if their impressions of their job security are anything to go by, a recent study has found. 200 employees of a major bank, working in locations throughout Australia, were asked about how secure they felt in their job. 50% said they felt very insecure, and another 20% said they felt quite insecure.

(ii) Dog owners need to take better care of their dogs. Well over half of the dogs which come into this veterinary surgery have some kind of illness or injury.

(iii) A phone-in poll on A Current Affair found that 96% of Australians thought that the asylum seekers on the Tampa should have been turned away.

(iv) A team of researchers was sent out onto the streets of Sydney, to find out what proportion of Australians were bed-wetters as children. Surprisingly, none of the 200 people interviewed had been bed-wetters. This must be problem which no longer exists.

(v) There is a strong consensus in the community that Nicotine-replacement patches should be given a government subsidy. A poll conducted by the manufacturers asked respondents whether they thought that the government should try harder to encourage smokers to give up the habit. An overwhelming 78% responded in the affirmative, including 60% of the smokers.