We have a team whose goal is to study websites which/that may not be secure.

[mark8]

Hi, hope it's OK for me to ask a second question today.

"We have a team whose goal is to study websites which/that may not be secure."

I am thinking that either could be OK depending upon the intent of the speaker. If the goal is to study the specific group of websites that may not be secure, then it should be "that". However, if the goal is to study all websites, and "may not be secure" refers to all websites and is just a bit of additional information, then "which" would be OK.

Thank you!!

 

[5jj]

Your thinking is largely correct. Only which works with your second idea; you also require a comma before which. That is more common with your first meaning, but some people use which; a comma would be incorrect.