But in truth, nothing will protect your equipment from a direct lightning strike to the wires nearby. This is true as much for the mains wires as for telephone wires. The amount of energy in a lightning strike is far too much for any practical domestic surge protector to be any use.
Which is why no phone service for four days everywhere in town is normal? A typical CO suffers 100 surges during every thunderstorm. Phone service is lost everywhere for four days after every thunderstorm?
Direct lightning strikes are routinely earthed without damage even to the protector. If a protector works by stopping or absorbing surges, then no protector survives. That popular myth (blocking surges) promoted in retail stores is not what a protector does. Protector diverts (shunts, connects, bonds, conducts) energy harmlessly to earth. Massive energy must be absorbed somewhere - in earth. Direct strikes that are properly earthed means a homeowner does not even know a surge existed.
Proper earthing means a short connection - low impedance - ie 'less than 3 meters'. That protector plugged into the wall is not earthed. Low impedance means 'less than 3 meters', no sharp wire bends, no splices, wire not inside metallic conduit, wire separated from all other wires, etc. Interior AC mains wire violates almost every 'low impedance' requirement. AC receptacle neutral or ground wire cannot provide necessary earthing.
An ethernet surge protector cannot dump surge energy to earth (when plugged in). Worse, it may provide a surge with more paths, destructively, via nearby appliances.
To have no surge damage, BT puts protectors as close to earth as possible AND up to 50 meters distant from electronics.
An ethernet protector (tens of volts) may interfere with or be destroyed by higher phone line voltages. Obviously, an ethernet protector is unacceptable for phone lines.
Protector for phone lines:
http://www.keison.co.uk/furse/furse11.htmalso has the necessary stud to make that short connection (no sharp bends, no spliced, separated from other wires etc) to earth.
And finally orainsear's question - is this the rare location where surges are more frequent?