Final answer:
Privacy online is essential to prevent identity theft and to protect one's online reputation, which can have long-term consequences on personal and professional opportunities.
Step-by-step explanation:
Considering privacy when posting information about oneself online is crucial for a couple of significant reasons. Firstly, individuals need their personal, financial, and medical information to remain private to avoid identity theft and unauthorized access to their accounts. Instances of large-scale data breaches, such as those at Target and JP Morgan, have highlighted how vulnerable online information can be. Secondly, the content people post on social networking sites can have long-term implications, such as affecting college admissions or future employment. Online reputation management is essential because once something is posted online, it can be difficult to remove completely and can perpetuate indefinitely in the public domain.