I don't think you can generalize as all guys who go on the internet are old men, but usually the guys who advance in a relationship are olod and perverted, but there are exceptions to the rule and some nice guys or gals could genuinely want a relationship on the internet because they are too shy normally, but it's whatever works for you!!
And I repped Link from this thread because he amused me and blah blah blah but basically..
One of my friends was chatting to this girl on the internet and when he asked for a picture (after much 'cyber sex' she gave him a picture of an over-weight 45 year-old!!!) XD
And she'd told him that she was a hot 17 year old!!!! *cracks up*