Like I said, you do not need to fill in your email address, and if you do, I'll never see it. I don't know why you say I ask for first and last name, because it isn't asked anywhere in the questionnaire. The personal infos I ask are the country you're from, your gender, year of birth, education level and whether you work or not. There's not much I can do with that information, except match nationality, gender, age and education level against knowledge of and opinion about the PAC and come up with some intelligent conclusions for my thesis.
I guess you can lock/delete the topic if you really don't trust it...
Again, I apologize for not speaking French