It would be interesting, yes, but not particularly meaningful without way more depth than a poll can provide.

• Did you pirate before you believed it was wrong, or while?
• EDIT: (Texrat-inspired) If before, have you gotten rid of it now?
• What sort of piracy, downloading instead of buying?
• Buying, then uploading or copy/sharing?
• Buying and installing on multiple machines?
• Using the OEM key for a new machine that came with Windows to install Windows on an old machine after you wipe the new one with a free OS?
• Buying in one format, then converting to another for your own use?
• Grabbing from ad-supported (TV/radio/web) and hoarding for possible rewatching?

What I'd find really interesting is a three-way poll:
Is software piracy ok?

• Yes, in general.
• Not in most cases, but with some exception for students with limited financial resources, etc.
• No, in general.