Vindication

As defined on dictionary.com:

vin·di·cate Audio Help /ˈvɪndɪˌkeɪt/ Pronunciation Key - Show Spelled Pronunciation[vin-di-keyt] Pronunciation Key - Show IPA Pronunciation –verb (used with object), -cat·ed, -cat·ing.

1.	to clear, as from an accusation, imputation, suspicion, or the like: to vindicate someone's honor.

2.	to afford justification for; justify: Subsequent events vindicated his policy.

3.	to uphold or justify by argument or evidence: to vindicate a claim.

4.	to assert, maintain, or defend (a right, cause, etc.) against opposition.

5.	to claim for oneself or another.

6.	Roman and Civil Law. to regain possession, under claim of title of property through legal procedure, or to assert one's right to possession.

7.	to get revenge for; avenge.

8.	Obsolete. to deliver from; liberate.

9.	Obsolete. to punish.

So... could someone please tell me what this poor machine could possibly be expecting??

Ticket machine in the metro stop near my office