You can say that, but if you write it that way you have a punctuation problem. Perhaps:Originally Posted by tmarkl
- We saw a lot of people, and many of them were sick.
You could also use a semicolon or a period in place of the comma.
You can't use them in place of whom, but you can use them, thus:Originally Posted by tmarkl
- Two of the seven defendants were absent from court. All of them have been charged with burglary.