The catch is that some people have no problems (eg the various webcams) others feel that publication without cause is invasion of privacy(which view is agreed to by much of European parliament as there is very likely to be a EU directive) - the data protection act applies to collection of data re living people ie in UK and Man you need a licence to do this, clearly state for what reasons you are gathering the information and you must have mechanisms by which people can see what data you have and can correct it. - I doubt if family historians would be seriously troubled though the 'one-name' collectors might.
For example my home telephone number is ex-directory - mainly because until it was I was continually pestered by double-glazing salespeople - I would be justifiably annoyed if some 'completest' family historian published it.
People in the public arena have to suffer more press/biographical intrusion than those who are not though continental europeans seem generally less intrusive than the gutter anglo-saxon press - however if the information does not add to the benefit of others why publish it? people are not stamps or objects in ones own private collection over which one can gloat having 'got the lot'.