One of my clients was told by Safe Harbor that they are the "private" Taxpayer's Advocate service. And no not the IRS: http://www.irs.gov/advocate/ He was told by the telemarketer: that he "came across his file" and thought he would give him a call about his tax case. I will say this is a really effective and clever sales tactic. But I wonder if he should tone down the "Taxpayer Advocate" part of sales pitch?
Nonetheless, keep your eyes and ears out for telemarketers. While their BBB records are impeccable for now: some important clues are
1. Are they overcharging you?
2. Are licensed tax professionals available? Do you know their names?
3. What role with the telemarketer play in the resolution of the case? Who will be accountable?
Here's another post about Colorado's tax lien telemarketing industry here: Tax Liens Incur Mailings and Phone Calls