Wait, maybe they were worried about plagiarism! I hope not though. Artists shouldn't shy away from the possibility of being copied. That's flattery. If you're the original and you know your work stands out, a little confidence will do you good.
Vandalism, maybe? People might make goofy poses beside the art pieces and upload them on Facebook? Come. On. Confidence. If your art is good, not even a team of kids making 'Rock on!' hand signs around it can destroy it.
Last guess --the art pieces are alive! They will die when exposed to round-the-clock flash photography like those Ocean Park fishies!
Then again, we already have Lego bricks at home... so, like I said, what's the point?
We stayed at the exhibit a grand total of 8 minutes. Geez, have we overstayed!