closes #1814

src/topics/tags.js

@@ -39,7 +39,8 @@ module.exports = function(Topics) {
 			return '';
 		}
 		tag = tag.trim().toLowerCase();
-		tag = tag.replace(/[,\/#!$%\^&\*;:{}=_`<>'"~()?\|]/g, '');
+		tag = tag.replace(/&/g, '&amp;');
+		tag = tag.replace(/[,\/#!$%\^\*;:{}=_`<>'"~()?\|]/g, '');
 		tag = tag.substr(0, meta.config.maximumTagLength || 15);
 		var matches = tag.match(/^[.-]*(.+?)[.-]*$/);
 		if (matches && matches.length > 1) {