Last week I took my Xperia Z2 to Vodafone for warranty repair for a faulty headphone jack. I performed a factory reset before handing phone over and received a Galaxy S3 mini as loan phone. I went through account set up on the S3 mini and then performed a factory reset on this when returning it to Vodafone on Friday last week when picking up the repair.

When looking at google contacts today, I have somehow inherited a huge number of new contacts (names and local numbers) under my account name?!

I can only assume that these were on the loan phone I received from Vodafone and google merged them under my account name when I set up my account on the S3 mini? Possible? Any other ideas on how this could happen?

I use 2-factor authentication on google and have reset my password today as a precaution, so unlikely someone has access to my account, but unsetttling, nonetheless, when you suddenly see a whole lot of foreign entries under your google contacts.