A heartbreaking cry rises from the common people as they face severe economic distress, having lost their agricultural lands simply to survive the crushing burden of government taxes. The primary approach among commentators is that this burden was a specific royal tax, such as a land tax demanded by the king [רש"י, רלב"ג, מצודת ציון, מלבי"ם].
To meet these heavy payments, the people were forced to borrow money from wealthier Jews. Securing these loans required them to mortgage their fields and vineyards [רלב"ג, אבן עזרא, שטיינזלץ]. By signing away their lands to repay the debts, the people were stripped of their only source of income. Their outcry expresses complete helplessness and existential dread, as losing their fields and vineyards meant they had nothing to eat and no way to survive in the future [רש"י, מצודת דוד].
While the pain of their poverty is immediate, this particular group is actually protesting debts that carried over from the past. These loans were taken out the previous year, which was not even a time of famine. Yet, the overwhelming demand to pay the king's tax was so severe that it forced them to mortgage their family properties back then, leading directly to their current state of desperation [מלבי"ם].