As AMR and CMR unions found out, anything that smells of a job action is illegal unless it follows the RLA pattern and can lead to very hefty fines. Other pilots have found this out- just posting something on an internet forum or letting the wrong person overhear you in the crew lounge talking about slowing things down, maintenance write up campaigns, sick outs, etc have led to job action (termination).
My personal opinion is that the RLA has outlived its usefulness and needs to be canned. Only then will airline management begin to take the pilots seriously. Won't happen anytime soon, however.