DTP Exposed

On the subject of actors, I narrowly missed seeing David Tennant's struggle with a sectarian past on Who do you Think you are?. Apparently, he got quite upset. Understandable and great 'human interest' telly. Anyway, he was only one of eight people doing the family thing this series, so this may not be such a case of DTP ubiquity as just 'Who do you Think we can get?'.