Internet searches reveal that Http://rexcurry.net is the first, or one of the first to use the phrases below.  It’s the site that coined the concepts "don't say public property" and "never say public property" while advocating that the term “government property” or "socialized property" should be substituted.  It is remarkable that these philosophical phrases have not been expressed before now on the internet.  To learn more on the related issue of "government schools" (not "public schools")  see http://rexcurry.net/schoolwords.html     For other fascinating rexisms with word-scoring and phrase-scoring results see http://rexcurry.net/full_blooded_tampan.html     The first number is the number of hits on the web, the second number is the number of hits in groups before rexcurry.net used the phrases on the internet.

"never say public property" 0, 0
“always say government property” 0, 0
"don't say public property"  0, 0
"call it government property" 0, 2
"don't call it public property" 0, 0
"call it socialized property" 0, 0  
"say socialized property" 0, 0

Here are some other comparison searches
"public property" 538,000    76,700
"government property"  144,000   21,000
"socialized property" 304      134
"socialised property"   78      9

"private property"   2,000,000    212,000
"non-government property"  280    27
"true public property"   87     83
"real public property"   231    80

"public park"   174,000     18,900
"government park"    4,850      222
"private park"     32,000    1,370

"public parks"   170,000     12,900
"government parks"    4,900      205
"private parks"     13,000      718