"this person has delated her/his questionnaire by herself/himself" ? It means that he/she has DELETED the questionnaire or profile. Most of the time I usually see that " this person has deleted her profile." I don't see any sense in only deleting the questionnaire. Sometimes the profile is deleted by the manager. So , this in my opinion is not blocking a person. When you block a person he/she cannot send you a letter or a wink. And he/she cannot look at your profile and pictures. To do "light blocking" you can put your profiles settings so , that only people who are in your favourite list can write to you and read your profile. But that means that some people can not contact you ..... I hope that you understand this a little ?