Facebook asks for Phone Verification immediately.

hey fellow blackhatters,

I have a problem registering new facebook accounts. I am using 1 private us proxy per account. With some cities I've had no problem but for LA and NYC accounts (I tried 3 different LA and 2 NYC proxies so far) facebook immediately asks for Phone Verification (luckily I've had couple of spare sim cards and facebook had no problem with them being european sim cards ).

I use firefox for this with foxyproxy
I use ccleaner between each attempt to register and clean EVERYTHING.
I have no other browser opened while doing this.

Do you know why facebook asks me that fast for phone verification? Is it proxy's fault or am I doing something wrong with cleaning up my pc?

If I buy US PVA's what's the chance facebook will become suspicious as soon as I log on them? or do I have to attract it's attention a bit longer?

Thanks in advance

Use Firefox Portable
Or use Website SMS Sender

Never used any of this. Will Firefox Portable increase my privacy while using proxy so there's less chance of leaking my real ip/last ip used?

I think that soon FB will always ask for a phone number. There are services that receive SMS and tell you code.