When can a lawyer use information learned during representation to benefit themselves?

The assertion that a lawyer can use information learned during representation to benefit themselves only if the client consents in writing is correct because it reflects the fundamental principle of client confidentiality and the lawyer's duty to act in the best interests of the client. Under the rules of professional conduct, specifically the duty of confidentiality, a lawyer is ethically bound to protect information relating to the representation of a client. This duty persists even after the representation has ended.

Written consent from the client provides clear evidence that the client is aware of and agrees to the lawyer's proposed use of the information. This complies with ethical standards, safeguarding the confidentiality of the client and ensuring that the lawyer does not exploit the client's information for personal gain without the client's knowledge and consent.

In contrast, the other options fail to uphold the ethical responsibilities lawyers have towards their clients. For example, acting on personal interest without consent would violate confidentiality, using information when the lawyer believes it will not cause harm doesn't sufficiently protect the client's rights, and utilizing information at any time after representation overlooks the ongoing nature of confidentiality obligations. Therefore, client consent is essential to ensure the ethical use of information by the attorney.