> If it hits 100k then it needs to be debated in parliament.
I don't think so. It says on the site "At 100,000 signatures, this petition will be considered for debate in Parliament".
I've seen people get excited about petitions before that got to 100,000 signatures and it all fizzled out, or it wasn't debated seriously in parliament. Often you will get a cookie cutter response with these petitions that is a paragraph long.
The reality is that most of the public are indifferent or supportive of the current legislation and most MPs know that.
> There would be more of an impact if, perhaps, everyone in the UK who has had to shut a web site because of this law wrote to their MP.
Each MP would get maybe a max of 10s of emails/letters each. Many of those MPs wouldn't even bother answering you. Those that do will often will probably give you the brush off.
I've written to my MP before (about encryption legislation), spent a lot of time presenting a clear and cogent argument and I got a "well I might have a chat with the home secretary" and they were still singing the same tune years later. What I was telling them was largely the same as other industry experts. They don't care and that is the unfortunate reality.
The fact is that the direction the UK government (doesn't matter whether it was Red Team or Blue Team) has been going in has been clear for well over a decade at this point. It would take a major political shake up for this to change IMHO.