> Do you think picket lines are illegal?

Picket lines that actually block other people from crossing instead of trying to persuade them not to? Yes. Use of threats, physically blocking, or just general impediment? Yes.

Not only does it violate state law (e.g. obstruction of free movement, interference with a business open to the public, false imprisonment, and assault are all offenses here in California depending on the facts), but it also violates NLRA rules.

(e.g. a recent labor case found repeated 1 to 4 minute "inadvertent" blockages unlawful -- https://www.laborrelationslawinsider.com/2018/02/the-nlrb-si...)

The Moscone Act that recognizes picketing federally also makes clear that this is not OK.

> It is not the intent of this section to permit conduct that is unlawful including breach of the peace, disorderly conduct, the unlawful blocking of access or egress to premises where a labor dispute exists, or other similar unlawful activity.