I always thought the signature was more about attribution rather than security. It's the thing that keeps you from later claiming that you had no knowledge of the transaction.

They can check the signature if you challenge a transaction. If it doesn't match, that supports your claim, otherwise it weakens it.

Some other signatures to try:

- VOID

- this is a stick up

- <a large swastika>

- I do not agree to pay these charges

- <the name of your waiter>

i think the reality is that if it's signed, however you choose to sign it, it protects the merchant from a chargeback ... Although, signing it with a stick figure is interesting. I wonder if the bank would consider that negligent if you decided to contest the charge.

If you had real guts, you'd contest the Mariah Carey charge. Seems like you have a strong case that you aren't her.