Люксембургский (де факто) плебисцит в октябре 41-го
October 10, 1941: Expecting their propaganda campaign to be successful, the occupation authorities organised a census, which included seemingly innocuous questions about nationality, mother tongue and ethnicity. Resistance organisations were quick to recognise this as a thinly disguised attempt to incorporate Luxembourg into the Reich and mounted a massive underground awareness-raising campaign ("Dräimol Lëtzebuergesch", eng: "Three times Luxembourgish"), turning the census into a referendum. The result was that 97% declared their Luxembourgish identity, often writing "Mir wëlle bleiwen wat mir sin" ("We wish to remain what we are") on the census forms. When the regime became aware of the fiasco, the census was immediately stopped. For the suppressed population, this was an enormous moral victory.

http://en.wikipedia.org/wiki/Occupation_of_Luxembourg_by_Nazi_Germany