Scanned copy of signatures included in email.

I have been wondering about scanned copies of physical signatures.  My financial institution sent me a document with a scanned copy of my signature on it.  I know that these signatures can be found in the county under public records, but I am wondering if it is a good idea security wise, to have these signatures flying around the internet with the inherent  insecure nature of unencrypted email.  They pointed out to me that they did not share anything that they are disallowed by law.  Unlike a physical letter that you sign to a friend, it is out there for others to see and one less piece of information for a scammer to steal an identity.

Am I just overthinking this or is this a real issue?

Thanks for your thoughts.