I think there is more to the story then is being reported. So two reasons they want to ban them is because farmers are leaving various debris on public roads and rather then cleaning up or not doing it they want to ban cyclists for "their safety". Also for the whole darting thing. That is very vague. Darting from where, under what circumstances? Maybe few cyclists were almost taken out by farmers vehicles and decided to take the whole lane every time they hear/see one approach from behind. As for law breaking part. What laws? Without more details it's hard to tell if there were any laws broken in the first place. Maybe farmers just saying it to rally support for their cause, or they consider cyclists not riding in the gutter/sidewalk as them breaking the laws. Just throwing some other alternatives before this turns in to another "those damn roadies blah blah blah" thread.