RS does not file lawsuits. Tax disputes are civil matters. 90% of all IRS tax disputes are settled administratively. IRS has absolutely no authority to call on local law enforcement for anything. Local law is never involved in IRS tax disputes. If LE is necessary, US Marshals do the job. IRS does not cold call anyone and all contacts are initiated by US mail.
I've had threatening calls asking me to call numbers 206-973-3241, 386-917-1152, 202-629-9364, and 213-289-9243, in order to avoid problems with the IRS.