alt Hacker NewsThe Instacart thing is just bluster. If they tried to file any lawsuit against these guys it's be an easy SLAPP (Strategic Lawsuit Against Public Participation) defense, which is a way to quickly throw out lawsuits in most states where corporations or others are trying to quell free speech.
I assume they would try to venue-shop for somewhere Anti-SLAPP protections are much weaker. Maryland and Virginia look particularly bad, for example (but IANAL).