Absolutely. I visit the USA a lot and, even though I have the ESTA visa waiver, I've sometimes still had the third degree from the CBP agent. Once I'd only brought $40 in cash with me because my UK bank didn't charge for foreign ATM withdrawals and so I thought it'd be easier to withdraw cash once I arrived. But I had three credit cards with me which had a credit line of about $30,000 and plenty of money in my current (checking) account, but the lack of cash on me was a red flag and I had to answer more questions about job, home, etc.. Fortunately I have a job which has a public profile, and the agent looked me up on our website. He then seemed satisfied that I, a middle-aged woman carrying a return ticket to the UK, with a good job, plenty of money, a paid-for home in a nice area and pets who live there, wasn't trying to sneak into the States to work illegally. Now I always make sure I have a few hundred $$ in cash with me, to avoid setting off any alarms.
Most of the time, though, the CBP agents are perfectly pleasant. One even winked at me and told me I looked hot, which I thought was kind of inappropriate (and utterly inaccurate, given I'd just got off a 7-hour flight and had been up for 4 hours before the flight and looked like crap). But I didn't say anything, for fear of him refusing me entry.