All:
Just a quick note... two months ago we noticed a new trend with both IRS and SSA scammers; they were appearing on toll-free numbers far more frequently. Doing carrier lookups on these toll free numbers have revealed that nearly all of them are on Grasshopper VOIP.
Grasshopper is a subsidiary of LogMeIn, Inc., another scammer-friendly company (they're the makers of GoToAssist).
We have turned in numbers to Grasshopper over and over by calling their sales and technical representatives directly, but given how there's been a mushrooming of numbers running on this carrier; it seems like it's another Peerless/Bandwidth.com scenario where the carrier knows about the criminals running felonious scams on their network but they feel like they can't screen that stuff out and likewise are lackadaisical about complaints.
Grasshopper appears to be offering a very stupid deal---they're offering flat-rate teaser contracts which most of these scammers are jumping on board with. In exchange for the flat-rate 8YY toll free forwarding (TFF), they're often also doing SIP cloud hosting for the scammer as well (meaning that the scammer is also using Grasshopper as their PBX in the cloud).
Grasshopper is still obligated to pay the network fees to other carriers who are terminating calls to Grasshopper numbers, so how Grasshopper deals with high-volume calling to their 8YY customers on these trial offer plans is up to them. (And THIS is why phone consumers need the ability to block entire phone carriers, not just individual numbers or rely on lists like NomoRobo. There's only a handful of VOIP carriers that look the other way and are happy to take scammer dollars, and very few of these scammers ever appear on a Tier 1 service)
It's very obvious to me with dialing scammers running on Grasshopper that they're still using a credit-balance system like almost all VOIP providers do (meaning; you prepay money to the VOIP phone company and they subtract from your credits for services). But it appears that features like voicemail run independent of whatever PBX is being used by the scammer... Grasshopper is hosting that. They only shut it all off when they "park" the number.
Technically so long as that voicemail is working, an SSA scammer running on Grasshopper 8YY can still continue to scam as victims will leave voicemails. Since the voicemail is hosted and sitting on giant cloud storage, that is hard even for me to fill up---and I'm an ace at clogging up voicemail.
So if you see any Grasshopper 8YY scammers (nearly all toll-free IRS/SSA is running on Grasshopper, or else it's usually Inteliquent), please tag me--let me know on Discord/whatever or tell one of the other old-timers with dialers. There's only a couple types of intensive dialing that will force either Grasshopper or the scammer to deactivate the #.
(Parking a number means taking it out of service, but holding it in reserve for the customer. Carriers park numbers when a customer isn't paying their bill/owes a balance or if the carrier requires SIP registration--when there's no actively registered extension/trunk attached to the number. "Unparking" puts the number back in service again and calls will connect through again.)