Security issues

What is Social Engineering (SE) ? And how many organizations take the counter-measures against SE attacks ? Lets look at the library , Wiki says :
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Social engineering is a collection of techniques used to manipulate people into performing actions or divulging confidential information.[1] While similar to a confidence trick or simple fraud, the term typically applies to trickery for information gathering or computer system access and in most cases the attacker never comes face-to-face with the victim.
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Technics :

1 Pretexting
2 Phishing
3 IVR/phone phishing
4 Trojan horse/gimmes
5 Road apple
6 Quid pro quo
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The most expensive security measures leave a Human component widely open , so we should always keep in mind what Really counts ..