Email to the support staff usually gets a good response - except sometimes!
My issue with Linkedin is that as soon as it was known what I do for a living I got belted by PLC salesmen, SCADA salesmen, partnership offers from Chine, India and Russia - got out of there all together and removed all traces. Sometimes it does not pay to try and help people!
If it a private group I may give it a go but will certainly provide very minimal information - if I can - on my account so I do not get belted like last time. Trouble with Linkedin is that if people pay the money they can find anyone!