Do you have birth dates for all for whom you don't have death dates?
If you do, you can use the File > Privatize option. However, you should be aware of a couple of things.
1) The File > Privatize feature goes back 120 years, to 01/09/1893, ie will privatize all born after that date without a death date or place. Most people would like to go back only 70-100 years, but FTM does not give you an option.
2) The File > Privatize feature will privatize some people born before 01/09/1893 for no particular reason. Whatever FTM engineers have done to construct that filter is imperfect.
If you want to see what will be happening in your file:
1) Go to the Family tab
2) At the very top button bar of your index, change the format to show birth date.
3) In the next next line down, change the sort to birth date
4) Now File > Privatize.
First, check to see if anyone before 1893 has been privatized. You will be able to tell because the birth date will have disappeared (don't worry - that's temporary). You will have to write these people down, turn off Privatize, enter a death date, ?, deceased, or dead in the death date field or "USA" in the death place field.
Then, check to see how privatization has worked for everyone born after 01/09/1893. If dates are showing, the info is public. If dates are not showing, they are privatized. You'd probably be safe to enter "USA" in the place field for everyone that is being privatized that was born 1893-1913 (ie over 100-120 years old).
Another option that won't be so much work: Export everyone in your file born before 1913 (or 1923 or 1933 or whatever). Then make your report in the exported file. This removes everyone living or dead born after your selected date, but is easier than the above work (depending on how big your file is.)