Oh dear, I talk about citizens' legal right to go about their lawful activities and, all of a sudden it as if I support their work. To be clear, I do not. Yet, to also be clear, I support their right to spread their beliefs in any way that secular law sanctions. I'd also support Scientologists' right to do so. To attribute sinister intent to the rank and file Witnesses is ridiculous - even though I see their organization as potentially unhelpful to some vulnerable people - and in some instances, downright damaging. And that's why the law also supports your right to speak out against it if you so choose - which you did. But - and this is what it also means to live in a free democratic society, I in turn have the right to disagree with what you did and it doesn't make what you did a crime for it is not. It is all allowable under law and to support the process is not necessarily supporting the content.
Regarding Oppostate's comments: I like your suggestion about approaching the elderly couple and talking to them about keeping themselves safe from the scorching sun. Kind and humane.