What is a possible effect of a resonant ground connection?

If a ground wire is a certain length (specifically an odd multiple of a quarter wavelength), it can act as a resonant antenna rather than an effective ground. This high-impedance state prevents RF from draining to the earth. As a result, RF energy builds up and high RF voltages can appear on the chassis or enclosures of your station equipment. This can cause 'RF bite' when you touch the equipment or cause malfunctioning of the gear. It does not primarily cause physical damage like corrosion or extreme overheating of the ground straps themselves, nor is it the cause of an audio ground loop.