Ohio:
Deductions from Wages
An employer may not deduct from an employee's wages, unless the employee has consented to the deduction in writing, damage or loss of wares, tools, or machinery destroyed or damaged by the employee. Ohio Rev. Code 4113.19
An employer may deduct employee authorized deduction, including, but not limited to:
purchase of United States savings bonds or corporate stocks or bonds,
a charitable contribution,
credit union savings or other regular savings program, or
repayment of a loan or other obligation.
Ohio Rev. Code 4113.15
federal wage deduction law:
http://www.dol.gov/whd/regs/compliance/whdfs16.pdf
An actual *wage garnishment* would require a creditor judgment against you and an actual court order. (& they can't take your complete pay check)
You can file a wage claim/complaint - here is a link to a claim form.
http://www.com.ohio.gov/laws/docs/laws_MINIMUM_WAGE_COMPLAINT.pdf (though it's only for minimum wage) You can also sue in small claims court if the amount qualifies (up to $3,000 Ohio). Over that amt. requires suing in a higher court.
Re your question, no - this is not legal!