I don't understand why you are redefining a call for ostracism as "deciding who your friends are" and then classify ostracism as "the opposite of harassment".

This pretty much looks like harassment to me:

"the developer community need to start ostracising people working for these companies. Don't hire former employees, don't hang hang out with people who work for these companies and conferences. Don't supply services to these companies (build their website, network...)."