I just got this in my e-mail:

Other than a few photos and short videos of the “kidnap”, missingz.com account contained the following manifesto:

We, the Z liberation cell, claim the responsibility behind the kidnapping of all the Zs from the Zaatar W Zeit signs.

The Z Liberation cell has no affiliation to any political leader, military or religious group.

Our cause is solely to liberate every single Z we find in town.

We want change and we aim to evolve.

More info to the public in due time. #MissingZ

“change” could be a hint to probably new items on their menu… and I expect the whole thing to turn into a competition the find the missing Z’s… Let’s wait and see!