I've noticed that for a lot of websites (google mail being an example) they ask you to provide you cell phone/ mobile number in order to text or call a verification. I understand that this is a good step in security for such websites to stop robot hacks and so on.
However, i always feel a bit iffy about giving my number out on websites and this was proven a good fear recently.
I gave my number to activate my gmail account a while back, and my phone has increasingly been flooded with phonecalls from some finance company asking if i need a loan. After several calls, several hang ups and several wake ups at 3am i screamed at the lady asking where she got my number and she responded from a gmail partner.
Don't they have an agreement not to give out your number?
Huh, strangely I don't think I really ever had to provide a cell phone number for stuff unless I was buying something or signing up for a real life event/ program. That stinks though, I hate when businesses call me :P