This is published on the London Police Website:

Fraud Alert
The London Police Fraud Unit would like to warn citizens about someone that is soliciting information over the telephone. The suspects are telling people that they are owed money by a utility company and then they are requesting the victim's bank account information.

These phone calls have been traced back to phone number (519) 858-1931. Due to phone number portability issues this phone number cannot be traced to the suspects nor can it be placed out of order.

You are reminded not to give out any personal information over the phone unless you are sure that you are speaking with a trusted source.

Anyone who may have information in relation to this scam, or the person or people associated to this phone number, is asked to call Crime Stoppers at 1-800-222-TIPS or the London Police Service at 661-5670.

I'm in the club now, pretty weird that its happening to so many people though.
I think it gets worse when you pick up, i've been called six times today already.

It could be a container phone number for services such as Magic Jack or long distance bu***hit!

Had a call from this number at 3:41am in the dead of night. ?No one was on the line when I answered it.   Glad to see I am not the only one but don't understand why it can't be traced.  Looks like a cell phone number throught Rogers as out cell phone has the 858 number preceeding our home phone number.

This number called my parents place and asked for me under my maiden name, I wasn't home and my parents answered they told them to call back in half an hour, when I got home I was curious so I called it back and it said the number was no longer in service, I googled the number seen it here and reported it to London Police, they advised to not give any personal information and to ignore the call completely

this number has also called my house a couple of times asking if i was using microsoft and saying he wanted to clean my software. First of all he asked for me by my roomates name and asked me if i was married. when i said no he didn't believe me. i told him that my roomate didn't have a computer only I did and he also told me that i was lying and that my "roomate" was my husband!!!!