The incident in which a toddler was killed is extremely sad, but it is all too easy to jump to false conclusions as to what may have helped prevent it. However, it should be quite clear that whenever a cut off plug is discarded the fuse should be immediately removed, that would ensure that there can be no access to a live wire. The same advice would apply equally to any equipment lead or appliance which is being discarded, it is extremely unlikely that a toddler would have the capacity to refit a fuse.
The overriding rule is that any plug, device or appliance which could be dangerous in the hands of a small child should be put beyond the reach of all such children.
The reasons why socket covers have no part to play in preventing such accidents are as follows:
1. If socket covers were used as a means of prevention, then to ensure that a child who has access to such a dangerous object as a cut-off plug (or for that matter, hair straighteners etc) does not plug the item in requires that there is no available power socket in the house NOT fitted with a socket cover.
2. To achieve the above it would be necessary to ensure that there are no sockets which are left with any device plugged in, as clearly a child capable of inserting a power plug is equally capable of removing another plug to do it. (This will immediately tell you that there must be no cordless phones, video games, radios, televisions, computers, chargers, table lamps, or any other device in use in the house, this is a somewhat unlikely scenario.)
3. However, there are no plug-in socket covers which have been shown to reliably prevent small children from removing them. There are whole socket covers available, but these either rely on simple clips, which cannot be regarded as childproof, or locks which are undesirable as they prevent immediate disconnection of appliances in an emergency (eg overheating), and in any case they are not suitable for use with plugs which incorporate a charger for a phone etc. The only reliable means of putting sockets beyond use of a child is to remove the sockets completely, or place a very heavy piece of furniture in front of them, clearly neither of these is a practical solution.
4. It is interesting to note that one of the proponents of using socket covers to prevent children plugging in dangerous items is Roger Cheetham, managing director of Clippasafe. This stretches credulity beyond limits as the product which Clippasafe manufactures is one which uses a plug (such as the one the which the child intends to insert) to remove the cover! How can that prevent a child plugging something in?
(http://www.clippasafe.co.uk/rsm/58/press-releases/?id=40 )
Any suggestion that socket covers will prevent children plugging in dangerous devices is seriously misguided, and serves only to dilute the essential message that dangerous plugs, leads and appliances must be kept beyond the reach of small children at all times.