I've done so for two companies but only to get direct deposit. One Canadian MSC only pays by direct deposit and requires you to fax or e-mail the info. It's not completely unheard of and doesn't necessarily mean you are being scammed. They pay much faster than all these other companies with their 30-45-90 Paypal only nonsense..
Your original post was kind of vague.. are you giving the banking info to get direct deposit? You never have to give out your bank info when signing up. Often companies will give you the option to waive entering that info upfront (e.g. BARE/BAI is one MSC that doesn't force you to enter it in). Only send banking info for direct deposit purposes and/or if you feel it's OK. Trust your gut.
Silver Certified ~ Shopping all of Toronto and beyond