Are Pledges To ISIS On Facebook Legally Binding?

If you make a pledge to ISIS on Facebook, are you legally bound to serve out the term of the pledge?  Will ISIS send some ISIS people to drag you away?  Will ISIS send a strongly-worded letter?  Will ISIS sue you to enforce the pledge?  Is it possible to send someone else to honor the pledge in your place?  Does ISIS have an official Pledge of Allegiance?  I pledge allegiance to the flag of the united caliphate of ISIS and to the caliph for which it stands one nation under god indivisible with liberty and justice for all.  That would be weird.