Various numbers including this one, on various sites. Some report it as the Multiple Sclerosis Society - however there are a lot of scammers out there to pretend to be legit charities to try and get your personal info. Never provide your info - if you want to get involved, look up the legit number and call them yourselves.
Note: I gave a donation In Memoriam and told the MS Society 'Do Not Solicit Further' - they harrassed monthly for two years in various formats (and I told them to stop EVERY TIME) until I finally wrote three letters proving 'abuse' to the Office of the Ombudsman before they finally stopped. They have their own call centres, so don't need to be 'renting' various numbers and faking who they are. So I find the rash of calls from all different call centres in the past month to be totally suspicious.
Legit Charities are exempt from the Canadian Do Not Call Registry, as are polling/market research firms (an election is coming up, the parties want to know what you think!)
Check the Rules on the Do Not Call list you belong to. In Canada, legal charities and polling companies are exempt; the rules do NOT apply to off-shore/foreign companies. Most of the scammer calls are from call centres in Pakistan or Nigeria, so write your elected official and tell them you support funding to stop these scamming calls; and to use our trade agreements to leverage their support to shut down organized crime. The U.S. has a similar list process, but different rules. And no they don't 'know you' - if your name is published in any kind of phone book, they simply purchase the database and load it into the computer and your name and info comes up. That's why these scammers try all kinds of calls to get your personal info, then sell the data to each other for various purposes (according to the RCMP).