These related Help pages may answer your question:

• What can I do to protect my eBay account?
  You can take a variety of steps to help keep your account secure. Click the link above to learn how to change your eBay password regularly, monitor your account for suspicious activity, install online protection software, and add extra protection with the PayPal Security Key. . . .
• What is a member identity?
  Your member identity is a representation of you within the eBay Community. eBay members must be at least 18 years old, have a valid email address, and register with valid and complete contact information. However, members are not allowed to misrepresent their identities or publish other members' contact information. Click the link above to learn more about the responsibilities that go with an eBay member's identity. . . .
• How do I report unauthorized use of my account?
  First, check with family members or others who use your account to be sure that they haven't made any changes. Then try to sign in to your account. If you're unable to sign in, you can contact eBay for help. . . .