Some people are excel at introspection and can tinker with their own psychology to tear down the scaffolding of the social engineers.

Say the engineers wish to make a population weak and pleasure seeking. While most would likely give in there will eventually be people that deliberately live harder lives because they see their own weaknesses. Maybe they would come to see destroying the conditioning as a greater happiness than what was given to them in the first place.

If they wish to use fear as a means of control people can develop courage as a response.

The only solution left is labelling these people undesirable to limit the spread of the anti-meme to others.

Social engineers also deal with diminishing returns.