Activity section under Contact disappeared for all my clients except their initial response

[Wendy2]

Whilst in Contact, the Activity section used to give me all of their movements, what links they were clicking through on etc. About 6 weeks ago the content disappeared for all of my Contacts except for their initial response. Any ideas why?

Thanks

[JustinPerkinsC]

Anything changed in the security settings changing access, or did you adjust any filters toggling off stuff in your views on contact records?