I don't think that is true. Plenty of companies are sued without notice for pate...

jamesaguilar on July 22, 2013 | parent | context | favorite | on: Ask HN: Take down my reverse-engineered Snapchat l...

I don't think that is true. Plenty of companies are sued without notice for patent infringement. It's not generally the case that you have to notify the parties to a suit before initiating it.