In the "real world" there is nothing to prevent someone from forging your real signature on a check or document or from disguising themselves as you and taking your place at an important business meeting. The digital equivalents can be slightly more secure, but nothing is ever perfect.
jim
Heh. Whoops. I may be a beginner but I'm not THAT green. I shoulda known better than to use that exact wording. Please excuse the inappropriate wording, all. Sincerely. Quentin Holte. ( aka Charles Choi. ) You are all the Buddha. - Last words of Buddha. If you see the Buddha, kill him. - Zen proverb.