It is. At the moment many Nostr clients generate a link preview when they encounter a link in a note. If this would be many it would effectively ddos the linked resource.
Discussion
It's kinda similar but not totally. Unlike Mastodon, the effect wouldn't be too severe as Nostr is built differently. You can read the other comments here in this thread.
The argument that relays won't generate link previews?
That is irrelevant as online Nostr clients will do.
It's not irrelevant. It's just that relays don't generate link previews, but clients do. That's the argument. And it's what differentiate #Nostr from Mastodon.
I like Mastodon and I want it to succeed. But I also believe that it needs to future out how to overcome this issue.
There are about 8000 Mastodon instances and about 18000 daily active Nostr clients at the moment. So there will be no big impact if a Nostr account with reach posts a note with a link. Generating the link preview on the client is worse, because they are many more then relays. It is just a matter of numbers if this will be a problem.
F.x. the Telegram messenger generates and caches link previews on their servers. They cannot let the clients do this, because they have channels with hundreds of thousands of participants. They even have a bot (Webpagebot) to update link previews.
X does generate link previews on their servers and other services do that also. The problem with Mastodon is that there are so many instances and every single instance federating a toot will generate the preview again.
Web-Servers have ways to mitigate the problem also. The first response to the resource may just return the open-graph tags in the head and a redirect to the real resource or code to populate the web page that is not executed while generating link previews. That preserves the server from generating and returning the full content.
If Nostr grows significantly generating link previews on the clients will become a problem. I'm sure there will be a addition to the protocol to add and/or cache link previews for a note and avoid doing that on every single client again and again.
Your argument seems reasonable. Unfortunately I can't argue further with my limit knowledge on this. Maybe someone with the technical know-hows can answer. nostr:nprofile1qqsrhuxx8l9ex335q7he0f09aej04zpazpl0ne2cgukyawd24mayt8gprfmhxue69uhhq7tjv9kkjepwve5kzar2v9nzucm0d5hszxmhwden5te0wfjkccte9emk2um5v4exucn5vvhxxmmd9uq3xamnwvaz7tmhda6zuat50phjummwv5hsx7c9z9, nostr:nprofile1qqsr9cvzwc652r4m83d86ykplrnm9dg5gwdvzzn8ameanlvut35wy3gpz3mhxue69uhhyetvv9ujuerpd46hxtnfduq3qamnwvaz7tmwdaehgu3wwa5kuegpzemhxue69uhhyetvv9ujuurjd9kkzmpwdejhglzevy3, nostr:nprofile1qqsyvrp9u6p0mfur9dfdru3d853tx9mdjuhkphxuxgfwmryja7zsvhqpzamhxue69uhhv6t5daezumn0wd68yvfwvdhk6tcpz9mhxue69uhkummnw3ezuamfdejj7qgwwaehxw309ahx7uewd3hkctcscpyug, nostr:nprofile1qqsw9n8heusyq0el9f99tveg7r0rhcu9tznatuekxt764m78ymqu36cpz4mhxue69uhkvun9deejuat50phjummwv5hsz8rhwden5te0wfjkccte9e3xjarrda5kuurpwf4jucm0d5hsz9thwden5te0wfjkccte9e6hg7r09ehkuef0avzrjf, nostr:nprofile1qqs04xzt6ldm9qhs0ctw0t58kf4z57umjzmjg6jywu0seadwtqqc75spz4mhxue69uhhyetvv9ujuerpd46hxtnfduhsz9mhwden5te0wfjkccte9ec8y6tdv9kzumn9wshszxnhwden5te0wpuhyctdd9jzuenfv96x5ctx9e3k7mf0dv4ph5, nostr:nprofile1qqszv6q4uryjzr06xfxxew34wwc5hmjfmfpqn229d72gfegsdn2q3fgpr3mhxue69uhhxct5v4kxc6t5v5hxs7njvscngwfwvdhk6tcpzfmhxue69uhkummnw3e82efwvdhk6tcpz4mhxue69uhhyetvv9ujuerpd46hxtnfduhsk7wj75, nostr:nprofile1qqsgzfdez8ksa9xmuvqg5zly3nl9e5xqkpvj8nllj9aw06ra4pqq3qcppemhxue69uhkummn9ekx7mp0qyg8wumn8ghj7mn0wd68ytnddakj7qg4waehxw309aex2mrp0yhxgctdw4eju6t09u87wetc does anyone have further take on this?