Unlawful assembly.
"In England, the offence was abolished in 1986, but it exists in other countries."[0]
"while freedom of association is used in the context of labor rights and in the Constitution of the United States is interpreted to mean both the freedom to assemble and the freedom to join an association"[1]
I wouldn't be too excited about police in my area invoking "unlawful assembly" willy-nilly, especially when followed up by the "identification of press" actions as described in the article.
I don't want to go too far off the deep end in commentary, but it's more anecdata pointing in an uncomfortable direction.