In The Netherlands, we had a non-binding referendum on this [1] (complete with misinformation, or downright propaganda, on TV). The vote against had a minor but significant win on the for. Result? 1) The law got active a few months later 2) A few minor changes were applied 3) The right for a non-binding referendum got removed from The Netherlands, citing we should either have a binding referendum or none at all.

[1] https://nl.wikipedia.org/wiki/Wet_op_de_inlichtingen-_en_vei... (article also available in German and Chinese)

Interesting, but I guess that considering that the govt. announced their intention to pass the law regardless of the result of the referendum my question should have been "under what circumstances can you imagine being given a _meaningful_ vote on mass surveillance?"

You can't. A democracy, and a binding referendum, stands on the shoulder of the public being informed and interested about matters. The public does not know enough about the topic. They can't, because the enemy listens as well in this global world. Hence, the proponents can pull FUD and appeal to authority at will.

I'm a proponent of binding referendum, but I don't see how it would solve the problem in this case.

Not many.