Explanation

Mack's actions violated the Standard relating to loyalty by calling his long-term client before leaving Firm 1.

Analysis of Each Action:

1. Calling long-term client before leaving Firm 1 (Violation):

• While employed by Firm 1, Mack owes loyalty to his current employer
• Soliciting business for a competing firm while still employed constitutes a breach of loyalty
• Even without a noncompete agreement, employees must not take actions that harm their current employer's interests while still employed

2. Soliciting former clients after joining Firm 2 (Not a violation):

• After leaving employment, professionals are generally permitted to solicit former clients
• Since Mack does not have a noncompete agreement, he can contact former clients
• Using social media to find and contact former clients is acceptable as long as he uses publicly available information (from memory in this case)

Key Principles:

• The duty of loyalty requires employees to act in the best interests of their employer while employed
• Pre-departure solicitation of clients for a new employer violates this duty
• Post-departure solicitation is generally permitted unless restricted by specific agreements

Therefore, only the pre-departure solicitation violates the Standard of loyalty.