Obviously they have been making calls for years. One of their current names is "AMVETS CDSI" that is the name of a multi-branched, twisted group of supposed charities claiming to help Vets. The calls are to solicit donations of clothes, etc. to be sold at their thrift store.
They used to use women calling from their home phones. Looks like they have moved up to full illegal telemarketers (calling for a charity does not exempt you from the DNC list).
Other names they use:
Maryland
Maryland Central Donations
Amvets
Central Donation Services Inc
Central Donations Services
Central Donations
CTRL Donations
Central Donation
It is all said above! Google the number and you will see it is a telemarketing company. Possibly they are paid per call with no requirement of a conversation. Thus the "hang up". What if we all sent a request to everyone in our address book to call 1-410-327-5900 and hang up just one time. I can imagine thousands of calls which could disturb, if not annoy, the operations of the telemarketers. "What comes around goes around" and "Do onto others as you would wish them do onto you".