Like any other information processing solutions, cyber protection technologies require ongoing support and maintenance to sustain their effectiveness. Otherwise, the protection strength will deteriorate over time. Example is the regular definition update of blacklisted codes (or malware).
Other than technology vendor support, peer support is also essential. We are not just acting as an individual in the cyber world. What we do will affect others. Something goes wrong will not just impact to own self but also bring adverse effects to the connected peers in the cyber world. Example is social engineering attack using compromised identity against that identity contacts.
Therefore, peers are important to provide a different support perspective. If peers see something unusual (IM, email from someone they know), contact that someone via trusted channel (say, a phone call) to verify. Sometimes, that someone might even not know the identity has been compromised and launching attack.