One reason why loan sharks are illegal is that their interest rates are often astronomical. 

While traditional lenders such as banks charge interest rates of around 5% to 30% 

loan sharks can charge rates that are much higher, sometimes reaching 100% or even more.

These high rates make it difficult for borrowers to repay their loans, and they can quickly become trapped in a cycle of debt 

Another reason why loan sharks are illegal is that they often use violent or illegal means to collect their debts 

They may threaten borrowers with physical harm or damage to their property 

Or they may resort to more subtle forms of coercion such as harassment or intimidation 

These tactics are not only morally reprehensible but are also illegal, and those who engage in them can face criminal charges.

Loan sharks also often target vulnerable populations such as low-income families or individuals with poor credit scores