The interesting about conspiracy theorists is that they rarely consider the possibility that, like Abu Graib, stupid things are often done by low-ranking idiots screwing around. In this case, it seems that three people (at least two of whom worked for companies contracting with the State Department) whose jobs involved updating records accessed the passport files of the three candidates. There is nothing yet about who else's records they may have been into - such as a spouse, an ex-boyfriend, Bill Gates or whoever. When I worked for the VA, a constant issue with people who had access to veterans' claim and medical files was curiosity - and the sanctions were immediate and severe.
As someone said earlier, the more important issue to me is that (since [metaphorically speaking] loud bells ring and flashing lights go off whenever someone gets into a file they shouldn't be in) the supervisory staff clearly tried to cover this up rather than immediately running it up the line. The government (and its contractors) should have learned long ago that cover-ups never work...rather, they result in greater problems than if the issue had been addressed openly and immediately. For example, one can point at Mei Lai, Pat Tillson and (again) Abu Graib.