My Fiance has a fairly common name, and is the owner of the associated gmail account (think John.Smith@gmail.com). Several older women in other states have the same name...and seem to repeatedly beleive they have her email. My fiance got so frustrated with Walmart orders, amazon orders, bills, personal emails being sent to her that she tracked one lady down and called her.
The lady got angry that my fiance was 'using her email address and hacking her' and had to have it repeatedly explained that the old lady's email address was in fact slightly different (number at the end). It keeps happening. the lady writes it down wrong, her husband enters it wrong, her HOA (at her new house) enters it wrong. When the HOA got it wrong we told them and they asked us to fix it for them...We finally seemed to get some purchase on behavior change when we cancelled one of her orders via email. But the amount of information/influence we had over her accounts with just email was amazing. At one point, her husband used my fiance's email to register a bank account. We called the bank and after explaining the situation were able to CORRECT the email address for her (we decided that a bank account was serious enough to fix it rather than just be annoyed).
I think its perfectly valid to be concerned this is malicious or evil...but so many people are just inept technology users.