I have had a lot of help from some GR members, over the years, but have been irritated, in the past, by some people asking to see my tree . No details are given of a name, dob etc. of the possible connection. My first response is to ask who, in my tree, he/she has a connection. On some occasions, "no response is the loud reply". 
One member in particular asked to view my tree. As usual, I asked which relative she was interested in. She replied that she was just interested in a particular surname in my tree. Sometime later, by coincidence, she asked for access again, but did not give the relative's name. I asked the same question as before - still no response. The member's surname was different on this occasion, but the christian name was the same. Perhaps she had married, or divorced. What she obviously did not realise was that when her e-mails were forwarded to me from GR, they were not shown as different members, but as the same member. Did she think I would not notice??
When contacting a possible relative, I always (hopefully) uncheck the box allowing access to my tree. I think this should, by default, be left unchecked. Inexperienced members may not notice this. I have had access to trees, which I am not interested in, for several years. I never give access to my GR tree, but direct people to my tree on Rootsweb, which gives privacy to living members. My only complaint here is, that Ancestry then take this info,(that I have worked hard on, and charges other people for the privilege.
Sorry for the rant folks. Been wanting to get that out of my system for ages.