Damn guys, 5 days after starting this thread an electrical surge fried my lan card . Getting some surge protectors for my cable line.Not rich, just stupid. As IceWolf said, you be OK if you know what you doing. And he meant, do your research by reading around and learn from others. They usually post their o/c results. If you venture, start low then crank it up little by little. Then when it starts locking up, crank it back down. If you feel uncomfortable, just don't do it and be happy and safe.
You guys use these? I use one for my electrical outlet but never thought about protecting my modem.