Calling Owners Using Phone Numbers on Real Estate Transfer Statement

[Joe Howell]

I am trying out some new strategies to find deals in my area.  One strategy is using my county assessor's website to find the current owner of properties, how much they paid for the property, size, number of units, etc.  One document I have found is the Real Estate Transfer Statement (Form 521), which includes the telephone number of the person buying and selling the property.  Does anyone know if it is legal to call the person(s) based upon the phone numbers found in these documents? (This is for the state of Nebraska, by the way) 

Thanks in advance!